Re: [phenixbb] High B-factors after Phenix restrained refinement -- peptide building

Hi Dialing, You should be able to build the peptide in either of 2 ways: 1. Cut out the density for the peptide with phenix.cut_out_density and build into cutout.mtz with phenix.build_one_model, supplying the sequence of the peptide, and not refining the model. This will just build the peptide. Then you can translate the model that is built back using phenix.cut_out_density. 2. Alternatively, you can put your data file and your map coefficients, and complete sequence file including the peptide into phenix.autobuild and it should try to build the peptide in addition to the rest of your model. You can also include your working model to speed it up. All the best, Tom T On Dec 16, 2011, at 1:04 AM, Dialing Pretty wrote:

Hi Nat,

I have a protein-peptide complex crystal, and I got the 3-D structure of the protein part in the complex by rigid body refinement with isomophous crystal crystal structure as the search model, and I got the peptide structure by Coot peptide building, then I refine the whole protein-peptide complex.

Will you please tell me which Phenix program can be used to build the peptide as I mentioned in the situation above? I want to get a Coot alternative for the peptide building.

I am looking forward to getting your reply.

Cheers,

Dialing

From: Nathaniel Echols To: PHENIX user mailing list Sent: Friday, 16 December 2011 3:31 PM Subject: Re: [phenixbb] High B-factors after Phenix restrained refinement

On Thu, Dec 15, 2011 at 2:20 PM, Da Duan <[email protected]> wrote:

...

I used Phenix AutoMR to solved a structure to 3.3A and after 1 round of rigidbody refinement with Phenix Refine I proceeded to restrained refinement. The R/Rfree from the refinement decreased nicely as expected but the B average is at ~100 (using Group B factor refinement option). I took the same model and mtz through Refmac and the B average is about ~40. Has anyone experienced this before? I am almost positive it maybe a setting issue in Phenix Refine that i should be looking at to get the B factors to refine correctly.

How are you calculating the average B? Refmac prints "residual" B-factors in the B column of ATOM records - these do not include the contribution from TLS and Ucryst (an overall B-factor for the entire crystal). In Phenix, the ATOM records always have the total isotropic B-factor, and this will always be higher than the equivalent in Refmac. So it's quite likely that both programs are correct, they're just reporting very different things. (And for what it's worth, a mean B-factor of 100 is totally normal at 3.3A resolution.)

-Nat _______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb

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Thomas C. Terwilliger Mail Stop M888 Los Alamos National Laboratory Los Alamos, NM 87545 Tel: 505-667-0072 email: [email protected] Fax: 505-665-3024 SOLVE web site: http://solve.lanl.gov PHENIX web site: http:www.phenix-online.org ISFI Integrated Center for Structure and Function Innovation web site: http://techcenter.mbi.ucla.edu TB Structural Genomics Consortium web site: http://www.doe-mbi.ucla.edu/TB CBSS Center for Bio-Security Science web site: http://www.lanl.gov/cbss