- phenixbb - phenix-online.org

So what is unique?
by Kenneth A. Satyshur 15 Jul '14

15 Jul '14

There is some disagreement on terms used to deposit data. We need a definition and an algorithm for each definition. "Unique Reflections" My definition is all the possible reflections out to the highest resolution reported not related by symmetry. Where can I find this? The .mtz contains a list of all HKL calculated to the highest resolution. Usually, we are not able to measure all these diffraction spots due to limits of the detector, mechanical limits, crystal orientation, etc. 'Total reflections' The depositions server asks for total reflections. I assume it wants only those unique reflections we were able to collect, regardless of the sigma cut off. These are called 'observed'. The total we use in refinement will be a subset of the 'unique observed' that are cut on sigma. However, some crystallographers believe that we should not cut on sigma since some of the intensities may in fact be zero. Is this a question for the Refmac and Phenix people? Please give us some guidance and maybe a reference or two that we can use. thanks -- Kenneth A. Satyshur, M.S.,Ph.D. Senior Scientist University of Wisconsin Madison, Wisconsin 53706 608-215-5207

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cifs still in pdb v2
by Guenter Fritz 14 Jul '14

14 Jul '14

Dear Pavel and Nat, can you include in future phenix versions the FAD.cif, NAD.cif and data_NAI.cif / NAI.cif in pdb v3? Currently both are still pdb v2. I usually simply copy the cifs pdb v3 into the mon_lib directory , but sometimes I forget it and stumble over it. Thanks and best wishes, Guenter

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Maximum-likelihood score calculation
by Jouko Virtanen 12 Jul '14

12 Jul '14

Hi all, I would like to calculate the maximum-likelihood score given an input structure and an mtz file. How can I do that? Thanks in advance. Best regards, Jouko

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Real space implementation of DEN refinement?
by Oliver Clarke 11 Jul '14

11 Jul '14

Hi all, Just wondering whether there is any capacity to include DEN restraints in phenix.real_space_refine, e.g. as implemented in the program DireX (see ref below), or any possibility of implementing such in a future release of PHENIX? This would be very handy for refinement of models into low resolution maps (particularly EM maps). Also, on a different but related topic, does anyone have any suggestions as to how to handle model validation (local and global) at low resolution in real-space? It seems as though there is not a solid consensus on how to handle this. Many thanks, Oliver. 1. Schröder, G. F., Brünger, A. T. & Levitt, M. Combining Efficient Conformational Sampling with a Deformable Elastic Network Model Facilitates Structure Refinement at Low Resolution. Structure 15, 1630–1641 (2007).)

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Twinning in data reduction and phenix.refine
by Chen Zhao 11 Jul '14

11 Jul '14

Dear all, I am now dealing with a pseudo-merohedral twin (3.2 A, P1 twinned into C2), and I have a couple of questions concerning the data reduction and refinement: 1) R-free flag in refinement a) For twin refinement, I know the reflections related by the twin law should have the same R-free flag. If I process my data in P1, and generate the R-free flag by phenix.refine using the key word xray_data.r_free_flags.use_lattice_symmetry=True, can phenix generate the R-free flags considering the 2-fold point group symmetry and deal with the twinning properly? b) I read that the R-factor could go down to around 40% in twin refinement in the presence of twinning even if the model is completely wrong. For my understanding, this could be due to the fact that the reflections are correlated by the twin law. If the R-free flags are chosen in the highest lattice symmetry, will the R-free still suffer from this problem? 2) Twin fraction In phenix.xtriage, the predicted twin fraction is about 30%. However, in phenix.refine, the twin_fraction is always between 46% to 50%. Why could this happen? 3) Data reduction I am not very clear about this point, since I just started dealing twinning. But what I am thinking is whether it is a good idea to merge the Friedel pair in the presence of twinning. Since the two twin domains have different hkl index if considering one as the reference, is the Friedel law still valid? This might be a very simple mathematical problem. I really appreciate your answers! Sincerely, Chen

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Anomalous or not?
by CPMAS Chen 10 Jul '14

10 Jul '14

Hi, Phenix Users, I recently collected data at SSRL. I used autoxds and multiscale to merge couple of datasets and hoped to see some anomalous signals. Now comes the questions. 1. if I use the default sigma(=2), then autoxds will report weak anomalous signals and leave the friedel flag off. If I lower sigma to 1.5, it will report strong anomalous signals. 2. when I used Xtriage under Phenix to check the data quality, it reported weak anomalous signal or at above 10A. 3. I used aimless (in CCP4) to merge data, it also reported weak anomalous signal. Which result should I trust? By the way, how can I view/display the ***.anamplot file, which is apparently xmgr format file, but I can not display in CCP4i. Thanks! -- *************************************************** Charles Chen Research Associate University of Pittsburgh School of Medicine Department of Anesthesiology ******************************************************

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Re: [phenixbb] Anomalous or not?
by Ryan Spencer 10 Jul '14

10 Jul '14

The question then becomes how do you know the bromine is in the crystal? Is it covalent on the protein? Is it covalent on the ligand? How do you know if the ligand is in the structure? We have seen rapid crystal degredation with Br at its edge. Do you see the resolution significantly degrade after a few frames? I don't think it's a processing issue with xds or with phenix. Ryan -------- Original message -------- From: CPMAS Chen <cpmasmit(a)gmail.com> Date: 07/10/2014 9:52 AM (GMT-08:00) To: Ryan Spencer <rspencer(a)uci.edu> Cc: Francis Reyes <Francis.Reyes(a)colorado.edu>,phenixbb(a)phenix-online.org Subject: Re: [phenixbb] Anomalous or not? Well, let me make this clear. 1. I am using Br anomalous signal to identify the potentially bound ligand. 2. I do shoot the crystals at 0.92A. 3. the different crystals have different resolution, but anomalous signal was weak as reported by autoxds. Charles On Thu, Jul 10, 2014 at 12:25 PM, Ryan Spencer <rspencer(a)uci.edu> wrote: So I assume you were not able to shoot the crystal at ~0.92 A at SSRL or are the crystals sensitive? If you were limited to the single wavelength beam which is around 1A you’re dealing with a really low f” of 0.5322. There have been crystals solved with Sulfur using an in-house Cu sources (takes a lot of merged sets and anomalous is stronger at certain crystal angles) which gives about the same anomalous scattering as Br. Is the bromine covalent or is it soaked ion? Alternatives – soak with potassium iodide and get a dataset from an in-house source (iodine f” 6.6 at 1.54), or at least the anomalous locations. You may get a partial model to use for replacement at that point. Did each processed dataset have the same level of anomalous signal when processed individually? Ryan From: phenixbb-bounces(a)phenix-online.org [mailto:[email protected]] On Behalf Of CPMAS Chen Sent: Thursday, July 10, 2014 8:55 AM To: Francis Reyes Cc: phenixbb(a)phenix-online.org Subject: Re: [phenixbb] Anomalous or not? Francis, My anomalous plot for Br is more like your Cobalt 1 site less redundancy. Ryan, As my Br anomalous signals are weak, I merged signals from multiple crystals. Meanwhile I am looking into the detail about the autoxds processing as suggested by Tim. Thanks, On Thu, Jul 10, 2014 at 10:02 AM, Francis Reyes <Francis.Reyes(a)colorado.edu> wrote: In addition to Tim's comments above, using loggraph to see the anomalous CC plot from scala is a good qualitative indicator of whether you have anomalous signal.. Some data points for what reasonable plots (and their corresponding XDS SigANO's) look like: https://dl.dropboxusercontent.com/u/19558536/AnomalousCC.pdf F On Jul 10, 2014, at 9:03 AM, CPMAS Chen <cpmasmit(a)gmail.com> wrote: > > Which result should I trust? By the way, how can I view/display the ***.anamplot file, which is apparently xmgr format file, but I can not display in CCP4i. > -- *************************************************** Charles Chen Research Associate University of Pittsburgh School of Medicine Department of Anesthesiology ****************************************************** -- *************************************************** Charles Chen Research Associate University of Pittsburgh School of Medicine Department of Anesthesiology ******************************************************

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Postdoctoral Position in Membrane Protein Structural Biology
by Noinaj, Nicholas (NIH/NIDDK) [E] 07 Jul '14

07 Jul '14

Two postdoctoral positions in structural biology are available starting in August in my new laboratory within the Biological Sciences department at Purdue University. As part of the Markey Center for Structural Biology, my lab will integrate electron microscopy and X-ray crystallography with biochemical methods to study the biogenesis of beta-barrel membrane proteins in Gram-negative bacteria with a focus on eventual therapeutic development against pathogenic strains of bacteria (See Noinaj et al., Structure (in press, 2014), Nature, 501:385-390 (2013), and Nature, 483:53-58 (2012)). The Markey Center for Structural Biology at Purdue is recognized worldwide for its leadership in structural biology of viruses, membrane proteins, receptors, signaling proteins and enzymes in addition to methods development in crystallography, NMR and electron microscopy. My lab is located within the Hockmeyer Hall of Structural Biology which boasts state-of-the-art shared resources including a Titan Krios cryo-TEM, Bruker Avance-III 800 MHz NMR, Rigaku X-ray generators and detectors, and other advanced instrumentation available at the Bindley Bioscience Center, the Birck Nanotechnology Center, and the new Center for Drug Discovery. In addition, Purdue is in close proximity to the Advanced Photon Source at Argonne National Lab for convenient access to synchrotron data collection. The successful candidate(s) should be highly motivated, have strong written and communication skills, have (or expect) a recent PhD in structural biology, biophysics, biochemistry, or other related field of study and have previous experience in working with membrane proteins and/or X-ray crystallography or electron microscopy. Applicants should send a CV, names of three referees and a statement describing your interests and relevant work experience to Nicholas Noinaj at nicholas.noinaj(a)gmail.com<mailto:[email protected]>. Nicholas Noinaj Purdue University Department of Biological Sciences 333 Hockmeyer Hall 915 W State St West Lafayette, IN 47907

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Autobuiold from polyalanine model
by Chieh Yin 07 Jul '14

07 Jul '14

Dear Phenix Users, I am doing the molecular replacement to solve a membrane protein structure(transmembrane and soluble domain). The structure of the soluble domain is known, 200AAs. And there is a homology structure of transmembrane domain, 350AAs. I used the polyalanine model of the homologous model of transmembrane domain to do the first search. I got a solution with TFZ 16. Then used the partial solution to do the second search with the soluble domain as the model.I also got a solution with TFZ about 15. The density map showed I got the right solution. And the simple rigid body refinement yielded a Rfactor/Rfree 0.29/0.32. Then I used the polyalanine model and the soluble domain as the starting model to do the phenix autobuild. But it seemed that Autobuild didn't replace the alanine with the real sequence AAs. I tried to set the rebuild in place to false but I still got the same result. The Autobuild even didn't change any amino aside reside from the starting model. I hope you could figure out the problem for me. Thank you in advance! Best regards, Jie

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distinguish between metals
by Aleksandar Bijelic 01 Jul '14

01 Jul '14

Dear phenix developers and users, I wanted to ask if there is a possibility to considerably distinguish betwenn two/three metals. I crystallized an iron-binding protein (transferrin in apo form) with a Ru- and Ga-compound. I see density in the metal-binding site which should come from the Ru/Ga metal since crystallization was done with the apo-form, but nevertheless I need to prove this. The wavelength of the X-ray was 1.02 Angstrom and the respective f''and f' values for the metals are +1.66e/+0.30e (Fe), +1.62/-0.5 (Ru) and +2.95/-0.76 (Ga). Is it possible to distinguish between Ru/Ga and Fe and thus to prove that Fe was not bound? The resolution is moderate with 3.1 angstrom and all metals are able to exhibit the same coordination geometry, thus you cannot distinguish according to the geometry. Unfortunately, I was also not able to measure the crystal with multiple wavelenghts because the crystals were very fragile. I hope you can help me and give me some advice. Thank you in advance. Best Regards, Aleks -- Aleksandar Bijelic, MSc. Institut für Biophysikalische Chemie Universität Wien Althanstrasse 14 1090 Wien Tel: +43 1 4277 52536 e-Mail:[email protected]

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mailing list
by Aleksandar Bijelic 01 Jul '14

01 Jul '14

aleksandar.bijeli(a)univie.ac.at -- Aleksandar Bijelic, MSc. Institut für Biophysikalische Chemie Universität Wien Althanstrasse 14 1090 Wien Tel: +43 1 4277 52536 e-Mail:[email protected]

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select sphere syntax
by Tanner, John J. 28 Jun '14

28 Jun '14

Is there a way to select a sphere of residues in the phenix.superpose_pdbs command, analogous to the "around" syntax in cns? I tried "within" and "around" in phenix.superpose_pdbs but got "Atom selection syntax error". Thanks. Jack Tanner John J. Tanner Professor of Biochemistry and Chemistry University of Missouri-Columbia 125 Chemistry Building Columbia, MO 65211 email: tannerjj(a)missouri.edu<mailto:[email protected]> phone: 573-884-1280 fax: 573-882-2754 http://faculty.missouri.edu/~tannerjj/tannergroup/tanner.html

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Coot DNA names
by Bradley Hintze 27 Jun '14

27 Jun '14

Hey Folks, Does anybody know a quick way to convert DNA atom names back to PDB standard after coot modifies them to match the ccp4 dictionary? Thanks -- Bradley J. Hintze Duke University PhD Candidate Department of Biochemistry

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quick R-value calculation
by Patrick Loll 27 Jun '14

27 Jun '14

I have a structure pulled from the PDB that contains a gnarly, complex ligand, for which I don't have a library. I just want to do a quick R-value calculation +/- ligand, and I don't want to go to the trouble of building and testing a library just for this purpose. Is there some way to induce phenix.refine or phenix.model_vs_data to do the R-value calculation even if it doesn't recognize the nonbonded energy type symbols? Thanks for any tips. Pat --------------------------------------------------------------------------------------- Patrick J. Loll, Ph. D. Professor of Biochemistry & Molecular Biology Director, Biochemistry Graduate Program Drexel University College of Medicine Room 10-102 New College Building 245 N. 15th St., Mailstop 497 Philadelphia, PA 19102-1192 USA (215) 762-7706 pat.loll(a)drexelmed.edu

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seeking help about running SCALEPACK2mtz
by chen c 26 Jun '14

26 Jun '14

Dear PHENIXBBers: I'e got a problem about data processing when running SCALEPACK2mtz. Hope you can give me some advice on that. Here's my problem: I have an .sca file processed by HKL2000 about 4 years ago, I just ran the Scalepack2mtz program in order to transform it into .mtz file. However, the program keeps running. To ensure that the Scalepack2mtz program is ok, I use another .sca file for verification and it turns out that this file for verification is successfully transformed into .mtz file within seconds. I checked the .log file, the program keeps running when there are the following messeages: "Mean acentric moments I from input data: <I^2>/^2 = 2.360 (Expected = 2.000, Perfect Twin = 1.500) <I^3>/^3 = 9.187 (Expected value = 6.000, Perfect Twin = 3.000) <I^4>/^4 = 52.348 (Expected value = 24.000, Perfect Twin = 7.500) Mean acentric moments I from anisotropically corrected data: <I^2>/^2 = 3.121 (Expected = 2.000, Perfect Twin = 1.500) <I^3>/^3 = 12.788 (Expected value = 6.000, Perfect Twin = 3.000) <I^4>/^4 = 57.952 (Expected value = 24.000, Perfect Twin = 7.500) " does this means that the .sca file isn't processed properly? I also checked the scale.log file, and there are the following messages: " Shell Summary of observation redundancies: Lower Upper % of reflections with given No. of observations limit limit 0 1 2 3 4 5-6 7-8 9-12 13-19 >19 total 50.00 5.60 5.9 6.1 18.0 15.1 26.9 19.7 8.3 0.0 0.0 0.0 94.1 5.60 4.45 7.9 9.4 13.0 12.9 23.2 27.5 6.1 0.0 0.0 0.0 92.1 4.45 3.88 19.2 5.6 13.3 13.5 20.4 21.9 6.0 0.0 0.0 0.0 80.8 3.88 3.53 31.9 6.5 11.6 11.3 14.9 17.9 5.8 0.0 0.0 0.0 68.1 3.53 3.28 2.4 4.7 11.3 15.3 23.5 34.1 8.7 0.0 0.0 0.0 97.6 3.28 3.08 0.2 3.6 7.0 15.4 23.7 40.1 9.9 0.0 0.0 0.0 99.8 3.08 2.93 0.4 4.4 8.7 16.8 21.1 41.3 7.2 0.0 0.0 0.0 99.6 2.93 2.80 4.2 8.0 12.7 15.2 20.3 33.7 6.0 0.0 0.0 0.0 95.8 2.80 2.69 15.4 9.1 14.0 13.8 19.2 25.2 3.3 0.0 0.0 0.0 84.6 2.69 2.60 31.6 16.2 11.7 14.2 13.7 10.6 2.0 0.0 0.0 0.0 68.4 All hkl 11.8 7.3 12.2 14.4 20.8 27.1 6.4 0.0 0.0 0.0 88.2 " This clearly indicates an ice ring problem in the data-collection process. However, the ice ring problem shouldn't have caused the error during the .sca to .mtz process. In fact, I have use it for structure-solvement, and currently the two R factor is around 30%. However, the large deviation of <I^3>/^3 or <I^4>/^4 do means something wrong. Would you tell me what exact mistakes did I make? Can I use this .sca file for subsequent structure solving and refinement? Great thanks for your help! best regards chen

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Anisotropic B-factor restraints
by Elke De Zitter 26 Jun '14

26 Jun '14

Dear All I'm refining a protein structure with a resolution of 1.25 A, using Phenix GUI version 1.9. I am refining the B-factors for the protein atoms anisotropic and those for the water molecules isotropic. How can I restrain the anisotropic B-factors so that bonded atoms have similar ellipsoids (like the SIMU and DELU commands in Shelx making the atoms moving similarly in direction and amount)? Thanks Elke Elke De Zitter PhD student, KU Leuven Biochemistry, Molecular and Structural Biology Celestijnenlaan 200f - bus 2404, 3001 Leuven Room 00.84, +32 16 3 26530

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Combining phases?
by Yuri 26 Jun '14

26 Jun '14

Dear All, Im struggling with a structure. I have a good native data set with resolution 2.1A and a data set with ok stats collect at low energy trying to extract some anomalous signal from intrinsic sulphur atoms (6/ASU/400aa). Using a model of one of the domains I got a MolRep solution that has somewhat convincing features in the electron density maps some portions of the structure but not in others. I also ran HySS and obtained some coordinates for the 6 sulphur atoms but the map here is uninterpretable. Xtriage suggests the anomalous is only good until about 8A so I am not that surprised. Is there any way I can try to combine my putative MolRep model and phases with the sulphur anomlaous signal and maybe get better maps to build into? If so, how would I do that using PHENIX? thanks for the help -- Yuri Pompeu, Ph.D.

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GRC/GRS Diffraction Methods
by Anastassis Perrakis 25 Jun '14

25 Jun '14

Dear all, I am sorry to send one more post to the already overloaded bb, but please let me remind you for the last time that the deadline for applications for the GRC and the GRS is approaching, and is only three days from now. http://www.grc.org/programs.aspx?id=11654 We are all looking forward to welcome you at Bates College in a month from now, and we do hope for a few more last minute participations: we need all of you to make it as exciting and fun as possible! Best regards, Tassos

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Multiple Metal Sites in Autosol
by Ryan Henry Gumpper 24 Jun '14

24 Jun '14

??Hello All, ?I have a question regarding the metal assignments when using Autosol to process SAD datasets. I am new to field and I want to make sure that I am doing things correctly. My enzyme should contain 2 metal sites, one with Cu and one with Fe. We collected data at the Fe-edge, the Cu-PreEdge, and the Cu-Edge for a comparison. When I tell Autosol to search for 1 Cu site, using the Cu-Edge data, and another heavy atom Fe, it finds 33 sites all Cu with 2 being Fe. Likewise, using the same dataset, when I include S as an additional anomalous scattering moiety, it will find 1 Cu in the correct position and 32 S atoms--my protein does not contain 32 S atoms. Finally, when I include every possibility that was in my crystallization buffer, this includes a fairly high concentration of MgCl2, and I tell it to search for 1 Cu site with the additional heavy atoms being Fe, S, Mg, and Cl, it seems that it is able to assign the Cu correctly, however it now gives Mg coordinated with Cu instead of H2O molecules, and this is not possible. Should I include Mg and Cl in the search? And S? Also, why would it not be finding the Fe? Furthermore, and most importantly, why is it assigning so many heavy atom sites? I am having similar problems with the other two data sets as well. Thank you very much in advance! Regards, Ryan Gumpper

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Re: [phenixbb] Iron (FE2) metalloprotein
by Nathaniel Echols 24 Jun '14

24 Jun '14

On Tue, Jun 24, 2014 at 1:11 AM, Egor Tchesnokov < etchesnokov(a)chemistry.otago.ac.nz> wrote: > Thank you for the comment. > The model I use for Phaser is coming from Sculptor, so it does not have > heteroatoms. > I introduce heteroatom (Fe) only after Phaser. I use Phaser-EP to find it, > eventhough it is obvious from the density. Then I merge Fe and Phaser.pdb > in Coot after which I feed it to ReadySet. So the pdb that I give to Refine > either have Fe with occupancy of 1, <1 or >1 (I tried both). I use PDB > editor to add charge, but the outcome is still the same. After refinement > Fe occupancy is either 1 or very close. > My apologies, I misinterpreted your message. Is this just a case of "name that blob?" If so, I suggest posting images of the density around the iron to the list (and probably ccp4bb as well) asking for suggestions. It's very likely that someone will have encountered similar density before. -Nat

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Iron (FE2) metalloprotein
by Egor Tchesnokov 24 Jun '14

24 Jun '14

Hello, Active site contains iron (FE2) coordinated by three histidines. After Phaser the active site does not contain un-explained green density. After Refinement blobs of various shapes appear in the vicinity and upto 3-4A of active site iron. Refinement is done using occupancy and anomalous of iron options. Buffers do not contain molecules that could fit in those blobs. Any suggestions? Thank you Egor

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Geometry problems
by Yarrow Madrona 23 Jun '14

23 Jun '14

Hello, I have a ligand bound to a heme and I have supplied a CIF for phenix in refinement. I did not include all atoms just, those close to the iron. Unfortunately, I am getting very large reported bond deviations for other atoms. For example I get: bond pdb="FE HEM A 410 " pdb=" N3 CPZ A 500 " ideal model delta sigma weight residual 2.100 4.054 -1.954 2.00e-01 2.50e+01 9.54e+01 N3 and FE are not bonded and not expected to be close to one another. it is not supported by the structure. I suspect that this is causing my overall bonds deviations to be ~0.03 even if I greatly reduce the weight of wxc. Is it necessary to enter all of these outliers into the .cif file or is there an easier way? Thank you.

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Sulfate at 3-fold axis
by Zhou, Tongqing (NIH/VRC) [E] 23 Jun '14

23 Jun '14

Dear Colleagues, I am refining a structure and there is a SO4 on the 3-fold axis. What I did was to put atom S and O1 on the 3-fold with occ=0.33, and O2 with occ=1, and no O3 and O4 in the pdb (O3 and O4 will be the symmetry of O2). But when I refine it, Phenix complains close non-bounded distances for both S and O1. Is there a way to refine this sulfate? Thanks! Best regards, Tongqing Tongqing Zhou, Ph.D. Staff Scientist Structural Biology Section Vaccine Research Center, NIAID/NIH Building 40, Room 4609B 40 Convent Drive, MSC3027 Bethesda, MD 20892 (301) 594-8710 (Tel) (301) 793-0794 (Cell) (301) 480-2658 (Fax) ****************************************************************************** The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. ******************************************************************

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after updating my system 1.9 1692
by Afshan Begum 23 Jun '14

23 Jun '14

Dear Developers, I am wondering why my system is getting too much slow after update the phenix new version??? before that its take few mints to finish my job but now its take more than 7 hour just finish one job .could you help me regarding this. Many thanks Best Regards AFSHAN

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Update waters and chain ID
by Scott Lovell 19 Jun '14

19 Jun '14

Hi All, I'm refining a structure (dev-1726) that contains 24 protein subunits which are assigned to chains A-X in the PDB file. Chains Y and Z are assigned to a couple of ligands and the ordered solvent molecules are chain w (lower case). I decided to give the "Update waters" option a try during refinement but it seems that the chain ID of the ordered solvent is changed to chain S by default. Since I already have a protein subunit assigned to chain S, the following error is obtained when I try to open the model in Coot (ERROR 39 READ: Duplicate sequence number and insertion code.). To enable visualization of the model in Coot, I can of course manually change the chain ID for the ordered solvent in the output PDB file using a text editor. However, is there a way to override the ordered solvent default chain ID in Phenix to prevent duplication? Thanks, Scott __________________________________ Scott Lovell Ph.D., Director Protein Structure Laboratory University of Kansas Del Shankel Structural Biology Center

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