April 2015 - phenixbb - phenix-online.org

mmCIF file must contain at least one data block
by Ursula Schulze-Gahmen 18 Dec '15

18 Dec '15

I am getting this thie error message mmCIF file must contain at least one data block when trying to run readyset or phenixrefine I cannot find anything wrong wqith my input files. What is the problem? Ursula -- Ursula Schulze-Gahmen, Ph.D. Project Scientist UC Berkeley, QB3 360 Stanley Hall #3220 Berkeley, CA 94720-3220 (510) 643 9491

3 3

labelit distl_minimum_number_spots_for_indexing
by Christian Roth 22 Sep '15

22 Sep '15

Dear Phenix-Team I installed the latest nightly build 1.8-1069. I tried to index some diffraction images and to overwrite the minimum usable spots for indesing I tried the suggested command. However If I try this command, it seems that it does not exist. At least in the list of the possible distl commands it does not show up. Do I have to install some additional stuff or change some preferences to get this command? Best Regards Christian

6 8

Refinement with new mtz.file
by Aleksandar Bijelic 14 Jul '15

14 Jul '15

Dear CCP4 user and experts, I refined (with PHENIX) a 3.0 A dataset obtaining Rfree of about 0.24 (with good geometry according to Ramachandran, Beta Outliers, etc.) .... Everything seems to be ok (especially in relation to the resolution) .... because the mtz.file I used was quite old and I cannot find my xscale.hkl file, I processed the data set again (this time with optimizng and polishing) and received a "better" file according to almost everything (resolution limit, I/sigma, CC(1/2), Rmeas), thus I used this new mtz.file and put it in my last refinement step (the refinement which led to the above mentioned Rfree = 0.24). Suprisingly, the refinement starts at Rwork = 0.18 and Rfree = 0.19 but ending up with 0.20 and 0.22, respectively. So I wanted to know if this is usual? I was expecting my data to become slightlly better but what is irritating me is the starting R-values of the refinement and that it get worse during refinement. Maybe I did something wrong? Is it reasonable to replace the mtz.file with a new one in the last refinement step or should I start the refinement from the scratch? In the sake of completeness, I deleted the header of the used pdb.file because of the R-flag error which occurs, since Phenix reconizes that the pdb.file was already used with other Rflags. Sorry, but I am still a beginner in this field, so I would be very grateful if somebody could explain me this situation and my mistake and if I need to start refinement from the beginning. Thank you in advance! Best Regards. Aleksandar -- ------------------------------------------- Aleksandar Bijelic, MSc. Institut für Biophysikalische Chemie Universität Wien Althanstrasse 14 A-1090 Wien Tel: +43 1 4277 52536 e-Mail: aleksandar.bijelic(a)univie.ac.at --------------------------------------------

7 10

Re: [phenixbb] Refinement
by Pavel Afonine 26 May '15

26 May '15

Hi Mohamed, > How do tell phenix.refine to not move my HEM ligand around? yes, you can exclude selected atoms from refinement of coordinates in Phenix refinement GUI: Refinement settings -> Modify selection for: XYZ coordinates -> Edit -> type atom selection in "Edit selected" field (under XYZ refinement) like "chain A and resseq 1" or "chain A and resname ATP" However, I would rather find why correct geometry is not preserved. > I have a cif file describing the ligand but in my case, I can see > clear density of it not following the ideal geometry. If you send me files (off mailing list of course!) I will see if I can explain it.. You can copy to Nigel too as chances are that if you choose to send files I will be talking to him anyway. > As an example, I have attached a screenshot from Coot. It's hard to infer what's going on from a static image.. > In fact, the C atom is covalently linked to the nearest Cys, so the > HEM side chain should be 'moved' into the density and the green blob > shouldn't be there. Is this link defined anywhere in restraints used in refinement? Pavel

5 7

SA
by Irina PROKHOROVA 01 May '15

01 May '15

Hello, I am trying to run coordinate refinement 5 cycles with first cycle of simulated annealing (torsion) via command line. Here is a part of my params file that I adapted from my colleges: refinement.main { number_of_macro_cycles = 5 target = *ml mlhl ml_sad ls simulated_annealing_torsion = True } simulated_annealing { mode = every_macro_cycle second_and_before_last once *first first_half } refinement.refine { strategy = *individual_sites individual_sites_real_space rigid_body \ individual_adp group_adp tls occupancies group_anomalous sites { individual = segid *A individual = segid *B } As a result I get the Error Unused parameter definitions: simulated_annealing.mode (file "refine.params", line 26) Could you help me with the syntax, please. Should I include sites definition for simulated annealing? Irina

2 3

Phenix.real_space_refine and B-factor
by Smith Liu 30 Apr '15

30 Apr '15

Dear All, By Phenix.real_space_refine if is very nic to fit a PDB into an EM map, and we can get a fitted PDB. However no matter what is the run strategy (default, morphing, local grid search, etc), in the got PDB the B-factors for each atom in the coordinates were always those from the original input PDB, which may make the B-factors in refined PDB meaningless. As finally we need to deposit the refined PDB and EM to the database, will you please explain how to settle the B-factor issues in the refined PDB related to Phenix.real_space_refine? Smith

2 1

on B-factor refine
by Smith Liu 29 Apr '15

29 Apr '15

Dear All， If in the Phenix refine GUI, I only want to refine based on individual B-factors, can I only click "individual B-factors" without cliking any other items in the "Strategy" and without clicking any items in the "Targets and weighting" and "other options"? Further, if I only click "XYZ cordinates" without cliking any other items in the "Strategy" and without clicking any items in the "Targets and weighting" and "other options", what the Phenix refine realy do? Smith

2 1

extra density for phosphorylated Thr
by Ursula Schulze-Gahmen 29 Apr '15

29 Apr '15

I have a structure with a phosphorylated Thr (TPO). As far as I can see, phenix recognizes the TPO residue, but the electron density maps have a large positive density around the side chain of this residue. Any suggestion what is wrong? Do I need a special definition file for the TPO? Ursula -- Ursula Schulze-Gahmen, Ph.D. Project Scientist UC Berkeley, QB3 360 Stanley Hall #3220 Berkeley, CA 94720-3220 (510) 643 9491

2 1

Number of reflections
by Ana Ramos 29 Apr '15

29 Apr '15

Dear all, I am finishing with the refinement of my structure and I noticed that the number of observed reflections used for refinement 36720 is less than 80 percent of observed reflections for data collection (172551). I am aware that the data collection statistics should be calculated in the same resolution range of refinement. Do you know the reason of this difference? I just followed the instructions from HKL where I indexed and scaled and then used Phenix for MR and refinement. Ana

3 2

on phenix.real_space_refine
by Smith Liu 29 Apr '15

29 Apr '15

Dear All, If with phenix.real_space_refine, I got a model (with PDB), in which there is a fragment containing several residues (not in continuation in the fragment), with side chains not fitting to the corresponding side chain density (or out of the density, but close to the density), which function(s) of phenix.real_space_refine (for example,minimization_global or local_grid_search?) can improve the fitting of the sidechains to the density? I am looking forward to getting your reply. Smith

2 1