- phenixbb - phenix-online.org

Re: [phenixbb] advice for refinement with anomalous information
by John Rose 27 Aug '10

27 Aug '10

Hi, I am refining my first structure (Cd-SAD) with the Phenix (GUI) and would like to refine anomalous f' and f". When i check the box, a menu appears and I have no idea of how to define the Cd atoms. I looked at the help and FAQ and found this: refinement.refine.anomalous_scatterers { group { selection = name BR f_prime = 0 f_double_prime = 0 refine = *f_prime *f_double_prime So I thought the name should be input as CD in the gui but when I submitted the refinement I got an error. Any help here would be appreciated? Thanks, John Rose

4 3

file type not supported???
by Joseph Noel 24 Aug '10

24 Aug '10

Hi All, I am having a problem that should be totally simple but I am stuck trying to find out what is happening. I use Text Wrangler on my Mac as a text editor of files. I have used it many many times to edit PDB files. It seems now that some PDB files that I have opened and removed a few lines now show up as an unrecognized file type when trying to read them into Phenix or into COOT. However, when I upload them on the Molprobity site they are read fine and processed. However, even the downloaded file from Molprobity gives the same error. I know it must be something simple but stumped and hoping someone else has experienced the same problem and has a quick fix. Thanks! Joe ___________________________________________________________ Joseph P. Noel, Ph.D. Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: noel(a)salk.edu Web Site (Salk): http://www.salk.edu/faculty/faculty_details.php?id=37 Web Site (HHMI): http://hhmi.org/research/investigators/noel.html ___________________________________________________________

2 1

Re: [phenixbb] phenix.ready_set hydrogens not compatable with coot library
by Joseph Noel 24 Aug '10

24 Aug '10

Hi All, Indeed even the latest COOT still relies on the old PDB format and hydrogens fly. Its probably not prudent to use hydrogens in refinement then remove them and add back each time. Kind of defeats the purpose of using them in the first place. Until COOT is updated I found a pretty easy way around things as long as you have access to the internet. Just use the MOLPROBITY site (http://molprobity.biochem.duke.edu/). In addition to it being a fantastic tool for really cleaning up structures, you can quickly upload your refined file from Phenix with hydrogens, then hit the button to downgrade to PDB v23. It creates the appropriate file with renamed hydrogens that work great in COOT. You can then re-upload the COOT rebuilt model and it will "upgrade" naming to the latest PDB version. Download that file and there you go for Phenix refinement. Sounds like a bit but very fast and easy to implement until COOT is upgraded. Joe ___________________________________________________________ Joseph P. Noel, Ph.D. Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: noel(a)salk.edu Web Site (Salk): http://www.salk.edu/faculty/faculty_details.php?id=37 Web Site (HHMI): http://hhmi.org/research/investigators/noel.html ___________________________________________________________

5 4

Phenix Structure Soluiton & Refinement webinar
by Angela Criswell 23 Aug '10

23 Aug '10

Dear colleagues, I would like to draw your attention to an upcoming educational webinar to be presented by Paul Adams titled "Structure Solution and Refinement with Phenix" which is scheduled to occur Thursday, August 26th at 10:00 PDT (13:00 PM EST /17:00 UTC/GMT). You can find more information including a registration link at the following site: http://www.rigaku.com/protein/webinars.html Best regards, Angela

2 1

Palestrant, Deborah is out of the office.
by deborah.palestrant＠novartis.com 23 Aug '10

23 Aug '10

I will be out of the office starting 08/23/2010 and will not return until 08/27/2010. I will respond to your message when I return.

1 0

labelit.version bug?
by Ben Eisenbraun 23 Aug '10

23 Aug '10

labelit seems to be working fine, but one of my users pointed this out to me: $ which labelit.version /programs/i386-linux/phenix/1.6.4-486/phenix-1.6.4-486/build/intel-linux-2.6-x86_64/bin/labelit.version $ labelit.version Traceback (most recent call last): File "/programs/i386-linux/phenix/1.6.4-486/phenix-1.6.4-486/labelit/command_line/version.py", line 18, in <module> run() File "/programs/i386-linux/phenix/1.6.4-486/phenix-1.6.4-486/labelit/command_line/version.py", line 7, in run assert (os.path.dirname(build) == os.path.dirname(repos)) AssertionError -ben -- | Ben Eisenbraun | Software Sysadmin | | Structural Biology Grid | http://sbgrid.org | | Harvard Medical School | http://hms.harvard.edu |

2 1

phenix.ready_set hydrogens not compatable with coot library
by amadrona＠uci.edu 23 Aug '10

23 Aug '10

hello, After reading many posts on the phenix and coot boards I realize that the hydrogens produced by phenix.ready_set are not compatable with coot. Specifically, coot does not recognize HB3 and HD3 hydrogens. When I do realspace refinement they fly off into space. I have edited HB3 to read HB2 and HB2 to read HB1 and everything works well. I was wondering if there is a fix for this besides editing the pdb each time you run phenix.ready_set. Is there a way to add HB3 hydrogens to the phenix library (CCP4 library)? Thank you -Yarrow

6 10

MD with phenix.refine?
by Ed Pozharski 20 Aug '10

20 Aug '10

Silly question: is there some way to run what would essentially be an MD simulation with phenix.refine? I mean, turn off X-ray-term by setting tardy.target_weights.fix_wxc=0, and then run cartesian dynamics? Ed. -- "I'd jump in myself, if I weren't so good at whistling." Julian, King of Lemurs

2 1

Ringer: A program to detect molecular motions by systematic X-ray electron-density sampling
by Terry Lang 20 Aug '10

20 Aug '10

The Alber lab at UC Berkeley is pleased to release of the code for Ringer version 1.0 (http://ucxray.berkeley.edu/ringer.htm). Ringer is a program to detect molecular motions by systematic X-ray electron-density sampling. The aim of Ringer is to go beyond static structural snapshots of proteins by uncovering structural ensembles in X-ray electron density. This information can reveal not only which parts of proteins are flexible and which parts are rigid, but it also can define alternate conformations that may be important for function. Alternate conformations of binding sites also may afford additional targets for drug design. The Ringer method is described in Lang et al. /Protein Sci/. 2010 Jul; 19(7):1420-31 <http://www.ncbi.nlm.nih.gov/pubmed/20499387>. An application of Ringer, determining the structural underpinnings of the side chain dynamics critical for the function of the enzyme proline isomerase, was published in Fraser JS et al. /Nature/. 2009 Dec 3;462(7273):669-73 <http://www.ncbi.nlm.nih.gov/pubmed/19956261>. Ringer is freely available to academics. -- PaulaTherese Lang Postdoctoral Scholar Alber Lab, UC Berkeley http://ucxray.berkeley.edu/ringer.htm

1 0

hydrogens in riding model create steric clashes after refinement
by amadrona＠uci.edu 20 Aug '10

20 Aug '10

Hi, I am having a problem with hydrogens causing steric clashes after refinement. I added hydrogens to my pdb using: "phenix.ready_set model.pdb". I was given two sets of coordinates (my model and a pdb for Iron atoms) I included this new model in the next round of refinement but I did not include the pdb for the Iron atoms. I ran refinement with the folowing parmeter file: refinement.main.ordered_solvent = true #refinement.main.ordered_solvent.mode=filter_only refinement.refine.strategy = individual_sites+individual_adp #refinement.refine.adp.individual.isotropic = "chain W" refinement.output.prefix = CIN4_refine refinement.output.serial = 18 refinement.output.write_def_file = True resolution is 1.37A with close to 400,000 unique observations (obs/param is still about 4) Stats: Rwork Rfree bonds angles start: .1444 .1723 .016 1.617 end: .1371 .1657 .010 1.301 I also ran wxu and wxc optimization from the command line. I know that the defualt is "riding-model" so that the hydrogen atoms are not refined. However, I thought that the program would be able to avoid steric clashes. Is there an aditional command I need to turn on to account for this? I am currently fixing every hydrogen that clashes on an individual basis in coot. There are also a handfull of hydrogens that exist out in space that I decided to delete. Thank you very much for your help. -Yarrow

4 11

altloc non-bonded interactions
by Paul Smith 20 Aug '10

20 Aug '10

Is it possible to tell phenix.refine to ignore certain non-bonded interactions? I have a structure at 1.1A with some interesting sulfate molecules that refuse to refine well. I suspect two positions are alternately occupied by sulfate in some cases and two water molecules in others. I would like to refine with both (a sulfate and two waters) with each component at 1/2 occupancy. With alternate conformations of a given sidechain, the two alternate locations automatically ignore one another w.r.t. non-bonded interactions. However, different residues, it would seem, do not. Has anyone encountered a similar situation or do the phenix gurus have any input? As an alternative, can I define an alternate sulfate residue with several missing atoms? Thanks in advance, --Paul

3 2

Re: [phenixbb] stuck with phenix refine
by Ian Munro Slaymaker 19 Aug '10

19 Aug '10

I also have been having a problem with phenix.refine freezing with no error message from the GUI. It usually freezes at the first macro cycle. I am using version 1.6.4-486. -Ian

3 4

Constraining carbohydrate conformation
by Kenneth Verstraete 19 Aug '10

19 Aug '10

Dear phenixbb users, I wonder how I can constrain the conformation of a NAG-residue during refinement. I have a dataset to 4.2 Angstrom. After refinement some sugars end up in the boat conformation. I would like to run the refinement so that the Asn side chain and the Asn-NAG linkage is refined (using xyz or torsion angle dynamics) but that the NAG-residue itself is considered as a rigid group. Maybe one way of doing this is constraining the bonds and angles of the NAG residue by the defining them as "custom bonds and angles" with sigma=0? Is there a possibility in phenix to generate these constraints from an ideal NAG-residue automatically? Thank you very much for you advice, Kenneth Verstraete

3 2

clean up temporary files
by Jianghai Zhu 18 Aug '10

18 Aug '10

Hi, I realize that after a phenix run, especially autobuild and autosol, there are a lot of temporary files. Is there a way to clean up the disk? Even the .geo file can be removed after some time, because it is huge and can be easily regenerated. -- Jianghai

4 3

ubuntu 10.04 phenix installation
by vincent rao 18 Aug '10

18 Aug '10

Dear Phenix bb user, i'm trying to install the latest version of phenix (1.6.4-486) on my pc with Ubuntu 10.04 installed. I'm using the*phenix-installer-1.6.4-486-intel-linux-2.6-x86_64-fc13.tar * installer. The installer complains that the * bundle-1.6.4-486-intel-linux-2.6-x86_64.tar.gz* is missing in the phenix-installer-1.6.4-486/bundles folder, and requires *bundle-1.6.4-486-intel-linux-2.6.tar.gz *to be present in this folder. So i simply renamed *bundle-1.6.4-486-intel-linux-2.6-x86_64.tar.gz *to *bundle-1.6.4-486-intel-linux-2.6.tar.gz *and this allowed the installation to complete without any further errors. However, when trying to start Phenix, i get the following error: laptop:~/Documents/installers/phenix-installer-1.6.4-486> phenix Traceback (most recent call last): File "/usr/local/phenix-1.6.4-486/phenix/wxGUI2/command_line/main.py", line 13, in <module> run(sys.argv[1:]) File "/usr/local/phenix-1.6.4-486/phenix/wxGUI2/command_line/main.py", line 7, in run from wxGUI2 import App File "/usr/local/phenix-1.6.4-486/phenix/wxGUI2/App.py", line 6, in <module> import wx.lib.dialogs File "/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/site-packages/wx-2.8-gtk2-ansi/wx/__init__.py", line 45, in <module> from wx._core import * File "/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/site-packages/wx-2.8-gtk2-ansi/wx/_core.py", line 4, in <module> import _core_ ImportError: /usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/site-packages/wx-2.8-gtk2-ansi/wx/_core_.so: wrong ELF class: ELFCLASS64 Not sure if this is of any use in solving the problem, but i typed the following command phenix.wxpython -c "import sys; print sys.path" and got the following output; ['', '/usr/local/phenix-1.6.4-486', '/usr/local/phenix-1.6.4-486/cctbx_project', '/usr/local/phenix-1.6.4-486/reel', '/usr/local/phenix-1.6.4-486/phaser', '/usr/local/phenix-1.6.4-486/tntbx', '/usr/local/phenix-1.6.4-486/phenix', '/usr/local/phenix-1.6.4-486/elbow', '/usr/local/phenix-1.6.4-486/PyQuante', '/usr/local/phenix-1.6.4-486/docutils', '/usr/local/phenix-1.6.4-486/PyCifRW', '/usr/local/phenix-1.6.4-486/cctbx_project/boost_adaptbx', '/usr/local/phenix-1.6.4-486/cctbx_project/libtbx/pythonpath', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/lib', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python26.zip', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/plat-linux2', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/lib-tk', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/lib-old', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/lib-dynload', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/site-packages', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/site-packages/Numeric', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/site-packages/PIL', '/usr/local/phenix-1.6.4-486/build/intel-linux-2.6/base/lib/python2.6/site-packages/wx-2.8-gtk2-ansi'] thanks

4 3

geometry weight and rmsd bonds - angles
by Lionel Costenaro 17 Aug '10

17 Aug '10

Hello, I'm using phenix.refine for the first time and have some problem to get it reach reasonable rmsd bonds (0.012-0.015) and angles (1.5-1.8). I set the bonds rmsd_max and angles rmsd_max to these values and try different values for: wxc_scale (from default 0.5 downto 0.015), wxu_scale (from default 1 down to 0.03), wc (from default 1 up to 8), with and without optimising wxc wxu. Whatever the parameters, phenix never reached final rmsd better than 0.022 and 2.2. I refine the structure with refmac so far, but need to refine the occupancies (so phenix). Am I doing something wrong? Should I just use phenix to refine only the occupancy (I am actually doing it)? Any help or comment are welcome. Some information: space group: P21, 2 molecules (180 aa) / au, 510 waters, about 20% alternate conformations, ligand covalently link to the protein (correct dictionary and link parameters for refmac or phenix -add link to cif), resolution: 1.32, refine xyz for all, Baniso for all (refmac), ncs not used, R 13.6 Rfree 17.7 fom 0.913 rmsd 0.012 1.56 (last refmac) phenix version 1.6 289 (gui) Best regards, Lionel

8 20

HKL_base
by Ed Pozharski 17 Aug '10

17 Aug '10

MTZ-files generated by phenix (at least some of them) are missing the base dataset (HKL_base) which is a requirement since CCP4 5.0. Is this deliberate? Ed. -- "I'd jump in myself, if I weren't so good at whistling." Julian, King of Lemurs

3 6

AutoSol scaling error
by Yogesh Gupta 17 Aug '10

17 Aug '10

I got following error while running MIR in phenix: "Failed to carry out AutoSol_scale_and_analyze_MIR: list index out of range". Could some one tell me how to fix this? Thanks, Yogesh

2 1

Re: [phenixbb] Restraints file for a new amino acid residue
by Joseph Noel 16 Aug '10

16 Aug '10

Pavel, I sent you the associated pdb file as an attachment. The site in question is 169 in both monomer A and monomer B. I think one way around the problem for me is to create alternative conformations for the residues on either end of the modified cysteine. In that way I can refine each as a section of alternative conformations and then I think things should link up both in Phenix and COOT. COOT is particularly problematic. It only recognizes conformer A and not any additional conformers for a particular position if the name of the amino acid changes. I guess my case is not that common - ie a mixture of oxidation states of a regular amino acid. Joe ___________________________________________________________ Joseph P. Noel, Ph.D. Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: noel(a)salk.edu Web Site (Salk): http://www.salk.edu/faculty/faculty_details.php?id=37 Web Site (HHMI): http://hhmi.org/research/investigators/noel.html ___________________________________________________________

1 0

Re: [phenixbb] Restraints file for a new amino acid residue
by Joseph Noel 13 Aug '10

13 Aug '10

Thanks all for the advice. Basically that is what I have been doing. It is actually an oxidized cysteine to sulfenic acid. I am refining the site as alternative conformers with the normal Cys, the single oxidation state to sulfenic acid (CSO) and the double to sulfinic acid (CSD). I know that CSO is in the phenix library but it adds hydrogens to the amino group every time I run elbow or ready set. I then I have to edit the PDB file to delete the hydrogen or Phenix will not refine. I also have problems in COOT. It will not let me move the residues torsional angles. I have checked other structures in the PDB and the density fits perfectly with the structures of many such oxidized systems but for some reason Phenix is giving me some problems. I was going to create a "new" residue and explicitly define the oxygen as charged rather then protonated since the pKa of sulfenic acid is quite low. Maybe the problems all stem from refining this particular position with three alternative "conformers", each conformer of which is chemically distinct. For now, I have CSO labeled as convention BCSO for conformer B. Cys is ACYS. Joe ___________________________________________________________ Joseph P. Noel, Ph.D. Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: noel(a)salk.edu Web Site (Salk): http://www.salk.edu/faculty/faculty_details.php?id=37 Web Site (HHMI): http://hhmi.org/research/investigators/noel.html ___________________________________________________________

2 1

Autobuild error message
by bschmidt＠berkeley.edu 13 Aug '10

13 Aug '10

Hello all, I am trying to use phenix.autobuild from the command line to generate either composite omit maps or prime and switch maps. In either case, when I try, the program starts to run for a while before failing and giving me the following error message: "Failed to carry out AutoBuild_build_cycle: Sorry...the file AutoBuild_run_2_/TEMP0/refine_pdb_in.mtz is missing..." I'm not sure why that would be the case, or where that mtz is supposed to come from. Can anyone explain what might be the problem? Thanks, Bryan

2 2

Phaser SAD module - resolution question
by Peter Grey 13 Aug '10

13 Aug '10

Dear Phenix community, I am using Phaser SAD module with a poor MR model to locate the initial heavy-atom sub-structure. I have a 3A dataset but the anomalous signal is weak at the higher resolution shells. I would like to ask for your advice regarding the resolution I should use in Phaser. I thought that for the sake of just locating the sites I should use relatively low resolution (let's say 3.5 or even 4A) and then run Phaser a second time. In this second run I would use the highest-resolution and let Phaser only refine the sites (located in the first run) during one cycle and calculate the combined phases. Thank you in advance for your suggestions and advice, Peter

2 1

Where to find optimized wxc_scale/wxu_scale weighting factors after optimization
by amadrona＠uci.edu 13 Aug '10

13 Aug '10

Hello, I ran a refinement optimizing geometry and B factor weighting factors using optimize_wxc=true optimize_wxu=true. I was given these statistics in the pdb header: Rwork Rfree Bonds Angles start .1588 .1838 .007 1.235 end .1454 .1780 .016 1.601 (1.37 A resolution) 1. I would like to find the optimized weighting factors in the log file but cannot. Instead I find the following (pasted below). However, the scale here doesn't make sense to me because many our greater than 0.5. How do I find the optimized values so that I can use them in further rounds of refinement? I'm sorry if this has been covered in previous posts but I could not find an answer. 2. Can anyone explain the concept of optimizing the B-factor? I don't understand how changing it brings you closer or further from an ideal model as oppose to xray. (which is how I make sense of refining the geometry) Thank you -Yarow ================================ xyz refinement =============================== Start r_work= 0.1462 r_free= 0.1784 bonds= 0.015 angles= 1.53 r_work= 0.1492 r_free= 0.1792 bonds= 0.005 angles= 1.08 scale= 1.00 r_work= 0.1484 r_free= 0.1788 bonds= 0.006 angles= 1.14 scale= 1.40 r_work= 0.1480 r_free= 0.1787 bonds= 0.007 angles= 1.19 scale= 1.80 r_work= 0.1476 r_free= 0.1785 bonds= 0.008 angles= 1.23 scale= 2.20 r_work= 0.1473 r_free= 0.1785 bonds= 0.008 angles= 1.26 scale= 2.60 r_work= 0.1471 r_free= 0.1784 bonds= 0.009 angles= 1.29 scale= 3.00 r_work= 0.1469 r_free= 0.1784 bonds= 0.010 angles= 1.32 scale= 3.40 r_work= 0.1467 r_free= 0.1783 bonds= 0.010 angles= 1.34 scale= 3.80 r_work= 0.1465 r_free= 0.1782 bonds= 0.011 angles= 1.36 scale= 4.20 r_work= 0.1464 r_free= 0.1782 bonds= 0.011 angles= 1.39 scale= 4.60 r_work= 0.1463 r_free= 0.1782 bonds= 0.011 angles= 1.40 scale= 5.00 r_work= 0.1461 r_free= 0.1781 bonds= 0.012 angles= 1.45 scale= 6.00 r_work= 0.1458 r_free= 0.1781 bonds= 0.013 angles= 1.49 scale= 7.00 r_work= 0.1456 r_free= 0.1781 bonds= 0.014 angles= 1.53 scale= 8.00 r_work= 0.1454 r_free= 0.1781 bonds= 0.015 angles= 1.57 scale= 9.00 r_work= 0.1453 r_free= 0.1780 bonds= 0.016 angles= 1.60 scale= 10.00 r_work= 0.1495 r_free= 0.1794 bonds= 0.005 angles= 1.05 scale= 0.85 r_work= 0.1501 r_free= 0.1797 bonds= 0.005 angles= 1.02 scale= 0.70 r_work= 0.1507 r_free= 0.1800 bonds= 0.004 angles= 0.98 scale= 0.55 Final r_work= 0.1453 r_free= 0.1780 bonds= 0.016 angles= 1.60

4 6

Restraints file for a new amino acid residue
by Joseph Noel 13 Aug '10

13 Aug '10

Hi All, How does one create a new CIF file using Elbow for a non-natural amino acid not found yet in the PDB? I know how to carry it out for the isolated residue readily (but of course thinks it is isolated and doesn't include the necessary peptide bonding) but how does one ensure the correct backbone restraints for it are included since it is not isolated but part of the chain? Joe ___________________________________________________________ Joseph P. Noel, Ph.D. Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: noel(a)salk.edu Web Site (Salk): http://www.salk.edu/faculty/faculty_details.php?id=37 Web Site (HHMI): http://hhmi.org/research/investigators/noel.html ___________________________________________________________

3 2

too many outliers
by intekhab alam 13 Aug '10

13 Aug '10

Hi there I have recently solved a structure at 2.71A resolution using CCP4 (Refmac5) with R and R free of 22 and 29 respectively. The model is nicely fitted in the map and everything looks except in some loop region where the map is not fitted well. I just finished modelling and checked ramachandran plot which is showing unreasonably high number of outliers (12%) with only 65% in the favoured region. I am thinking to use phenix_refine with simulated annaeling and using the option fix bad chain rotamers. What else i can do aprt from this. i will be highly thankful for the suggestions. Apart from this can anyone let me know how -- INTEKHAB ALAM LABORATORY OF STRUCTURAL BIOINFORMATICS KOREA UNIVERSITY, SEOUL

2 1