February 2009 - phenixbb - phenix-online.org

modification of nonbonded geo restraints between symmetry mates
by Alejandro Buschiazzo 03 Feb '09

03 Feb '09

Dear PHENIX users, I wonder what is the 'correct' way of (re)defining geometric restraints among atoms. Here's what I need to do : I have several cations that are chelated by protein residues; some of them involve residues from the same monomer, yet others involve atoms from both the ASU monomer as well as crystal neighbors (i.e. symmetry mates). I see that in the .geo file, these parameters are taken into account as nonbonded simple and nonbonded asu respectively ... how can I change the ideal distances to get proper Zn+2 coordination bonds for both kind of partners? Thank you in advance for your help! -- Alejandro Buschiazzo, PhD Research Scientist Laboratory of Protein Crystallography Pasteur Institute of Montevideo Mataojo 2020 Montevideo 11400 URUGUAY Phone: +5982 5220910 int. 120 Fax: +5982 5224185

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map coeffs?
by Walter Novak 03 Feb '09

03 Feb '09

Hi all, I am doing joint X-ray neutron refinement, and in the 1.4-3 version I now get twice the number of choices of map coefficients when opening the mtz. Half now have "no_fill" with them. I am assuming that the difference between maps has something to do with missing Fobs, is that right? Which maps should I be looking at then? Thanks, Wally Walter R.P. Novak, Ph.D. Postdoctoral Fellow Rosenstiel Basic Medical Research Center Brandeis University 415 South St. MS 029 Waltham, MA 02454-9110 Phone: (781) 736-4944 Fax: (781) 736-2405

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TLS + anisotropic ADP mixed refinement
by Scott Classen 02 Feb '09

02 Feb '09

I am trying to perform refinement on a model with three chains (two protein and one DNA... plus water, Cl, and a few other solventy things). The B factors for chain A are generally better than for the other two and I am thinking that the resolution (1.8Å) warrants attempting anisotropic individual adp refinement for at least chain A, and then using TLS for the other two. So my strategy is: *individual_sites *individual_adp *tls *occupancies adp.individual.isotropic = "not Chain A" adp.individual.anisotropic = "Chain A" adp.tls = "Chain B" adp.tls = "Chain D" Previously the model had only been refined with individual isotropic adp (no TLS). The starting model has an r_work=0.2079 and r_free=0.2427. With this new aniso/TLS strategy in the first macrocycle when it gets to the initial TLS refinement it completely blows up with r_work and r_free both going up to 60% have I specified my refinement with bad syntax? or is this even possible with phenix.refine? I can submit more of the log file if you're interested. Thanks, Scott ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Scott Classen, Ph.D. SIBYLS Beamline 12.3.1 http://bl1231.als.lbl.gov Advanced Light Source Lawrence Berkeley National Laboratory 1 Cyclotron Rd MS6R2100 Berkeley, CA 94720 C) 510.206.4418 O) 510.495.2697 Beamline) 510.495.2134 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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can phenix.refine calculate r_work and r_free without doing refinement?
by Scott Classen 02 Feb '09

02 Feb '09

Hi all, I was wondering if phenix can calculate r_work and r_free without refinement, sort of like the model_stats from CNS. Thanks, Scott ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Scott Classen, Ph.D. SIBYLS Beamline 12.3.1 http://bl1231.als.lbl.gov Advanced Light Source Lawrence Berkeley National Laboratory 1 Cyclotron Rd MS6R2100 Berkeley, CA 94720 C) 510.206.4418 O) 510.495.2697 Beamline) 510.495.2134 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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