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Unknown atoms in refinement
by Jeff Habel 06 Sep '07

06 Sep '07

What's the best way of dealing with unknown atoms (UNK) in phenix.refine? I have a long disordered loop that runs basically the length of the protein on the back side and there is a single "amino acid" in the middle that I'm trying to model as UNK. I can run a round of refmac and auto generate a lib file with my ligand and the unk atoms but phenix.refine balks at that with respect to the Van der Waals radii. Thanks for the help, -Jeff

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wxu_scale during TLS + INDIVIDUAL_ADP refinement
by Jose M de Pereda 06 Sep '07

06 Sep '07

Dear colleagues, I am refining a structure with phenix.refine (cci_apps 2007_08_18_1856). The strategy includes refinement of tls, individual_adp, and individual_sites (during the same run.) In order to test different restraints for ADP´s refinement, I have changed the value of the wxu_scale from the default. Yet, the value of the wxu_scale parameter is always automatically reset to the same value as indicated in the log file under the section "Automatic adjustment due to TLS refinement". That is, phenix.refine uses in all cases the same wxu_scale independently of the value I set in the definitions file. Of course, when TLS refinement is not done, the wxu_scale value remains as specified. I would appreciate if someone could indicate me how to modify the ADPs restraints when doing TLS refinement. Cheers Jose -- -------------------------------------------------- Jose M de Pereda, PhD Centro de Investigación del Cáncer Spanish National Research Council - U. Salamanca Campus Unamuno s/n E-37007 Salamanca, Spain Phone: +34-923-294819 Fax: +34-923-294795 http://xtal.cicancer.org/ -------------------------------------------------

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statistics for highest shell in phenix.refine
by michael hothorn 05 Sep '07

05 Sep '07

Dear all, For the crystallographic table in my manuscript, can I define a highest shell in phenix.refine and have it output the refinement statistics for this range? If not, how can I calculate the highest shell statistics using the same parameters as used for the overall refinment? Thanks Michael

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Re: [phenixbb] selective nonbonded restraint removal
by Cathy Lawson 05 Sep '07

05 Sep '07

Thanks to all who replied. And thank you Ralf for your suggestion (quoted below), this worked very nicely! Somehow I missed this possibility in the online documentation. To reply to Pavel's question regarding how I figured out that tris is present at 1/2 occupancy: (1) density was first modelled with waters but they were too close together, and there was a fairly clear tetrahedral shape. (2) phosphate didn't refine well -- lead to huge negative difference peak at the P atom. (3) only other tetrahedral shape molecule in the soup was tris (TAM), and after refining just the tetrahedral core it was possible to see where the three arms extended. (4) b-factors for the tris were high relative surrounding protein atoms, and extraneous density suggested two alternate conformations for the nearby arg side-chain, one of which is too close to realistically exist next to the tris ligand. the other clue was that trial occupancy refinement of all atoms put most tris atoms in the 0.4-0.6 occupancy range. (5) tris with 0.5 occupancy, arg with two alt confs, plus a few waters at 0.5 occupancy is so far the best model with no significant different densities for this region. (6) the modelling will need to be confirmed with an SA omit ... > Hi Cathy, > > > The density suggests that when tris is not there, > > a side chain moves very close to that position > > You could model this with alternative conformations. If you assign > "altloc" A and B to two conformers of your protein, and just, say, B > to your TAM, then the ligand would only "see" your B protein. If you > don't define the B conformer (no atoms) then TAM wouldn't see that > part of the protein at all. > Actually, this approach seems better to me than working with > atom selections. > > Ralf

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Re: [phenixbb] selective nonbonded restraint removal
by Cathy Lawson 05 Sep '07

05 Sep '07

Hi Ralf, That is disappointing. Lovely maps produced after a few phenix.refine runs for a 1.6 A structure revealed an unexpected tris ligand (TAM) with occupancy ~0.5. The density suggests that when tris is not there, a side chain moves very close to that position, thus my question. In other regards phenix seems a great step forward in automating refinement, and I look forward to new developments. best wishes, Cathy > Hi Cathy, > > > Is it possible to turn off nonbonded restraints for particular > > residues/monomers, or for atoms with occupancy less than 1.0? > > Nope, sorry. It is on the (long) to-do list. > BTW: each time someone asks the priority goes up. > > Ralf

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selective nonbonded restraint removal
by Cathy Lawson 04 Sep '07

04 Sep '07

Hi Phenix bber's, I have been trying out phenix.refine and like it very much so far. Is it possible to turn off nonbonded restraints for particular residues/monomers, or for atoms with occupancy less than 1.0? Thanks, Cathy Lawson /////////////////////////////////////////////////////// http://rutchem.rutgers.edu/~lawson

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SAD related query
by tara kashav 04 Sep '07

04 Sep '07

Dear all, I am a novice user of phenix. I am trying to obtain phases for SAD dataset collected at 2.5 angs from autosol.But when i give the phases to autobuild, the R-factor is not decreasing below 49%. Also, in warp, it is unable to built with a message "encounterd an unknown element". Can someone suggest me what could be the problem. Thanks for any suggestion in advance. Tara Kashav On 9/3/07, phenixbb-request(a)phenix-online.org < phenixbb-request(a)phenix-online.org> wrote: > > Send phenixbb mailing list submissions to > phenixbb(a)phenix-online.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.phenix-online.org/mailman/listinfo/phenixbb > or, via email, send a message with subject or body 'help' to > phenixbb-request(a)phenix-online.org > > You can reach the person managing the list at > phenixbb-owner(a)phenix-online.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of phenixbb digest..." > > > Today's Topics: > > 1. command-line Patterson maps (Bryan W. Lepore) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 2 Sep 2007 00:07:51 -0500 (CDT) > From: "Bryan W. Lepore" <bryanlepore(a)mail.utexas.edu> > Subject: [phenixbb] command-line Patterson maps > To: phenixbb(a)phenix-online.org > Message-ID: > < > Pine.LNX.4.64.0709020001190.16588(a)cpe-70-116-17-26.austin.res.rr.com> > Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed > > will phenix calculate Pattersons from trial sites or a reflection file on > the command line? i.e. something besides hacking what is already there. > > e.g. cns has predict_patterson.inp. i can't seem to find a way to do it > from the command line - such as `phenix.patterson --sg=94 > reflections.mtz`. i saw phenix.maps but that looks like electron density > only. > > -bryan > > > ------------------------------ > > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://www.phenix-online.org/mailman/listinfo/phenixbb > > > End of phenixbb Digest, Vol 22, Issue 1 > *************************************** > -- Tara Kashav, Dr. S. Gourinath's Lab, Lab No 430, School of Life Sciences, Jawaharlal Nehru University, New Delhi - 110067

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command-line Patterson maps
by Bryan W. Lepore 04 Sep '07

04 Sep '07

will phenix calculate Pattersons from trial sites or a reflection file on the command line? i.e. something besides hacking what is already there. e.g. cns has predict_patterson.inp. i can't seem to find a way to do it from the command line - such as `phenix.patterson --sg=94 reflections.mtz`. i saw phenix.maps but that looks like electron density only. -bryan

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ligand restraints
by Jeff Habel 30 Aug '07

30 Aug '07

I have a ligand with two phenyl rings where 2Fo and difference density clearly shows some torsion angle between the two rings. However, no matter how many times I tilt one ring refinement always makes them coplanar. Is there an option that I can use in phenix.refine to prevent the co-planarity or how do people typically handle this situation? Thanks for the help. All the best, -Jeff **************************************** Jeff Habel PhD Scripps Florida Drug Discovery 5353 Parkside Dr, RF-1 Rm 102 Jupiter, FL 33458 Phone: 561-799-8849 Fax: 561-799-8957 Email: jhabel(a)scripps.edu *****************************************

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Turing off Auto-Modify initial isotropic ADP
by James Fraser 30 Aug '07

30 Aug '07

I'm trying to do an Fcalc with "main.number_of_macro_cycles=0 main.bulk_solvent_and_scale=false export_final_f_model=mtz ", but the b-factors get randomized before the 0th cycle of refinement (see excerpt from log below). Is there anyway to turn this off? Thanks, jf <<LOG FILE>> ----------Auto-Modify initial isotropic ADP---------- Randomizing |-ADP statistics (Wilson B = -4.823)------------------------------------------| .... -- James Fraser jamesfraser(a)berkeley.edu Alber Lab 356 Stanley Hall, QB3 UC Berkeley Berkeley, CA 94720 http://ucxray.berkeley.edu/~jfraser/

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