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C-alpha r.m.s.d. calculation before and after structural alignment
by Bret Wallace 04 Apr '13

04 Apr '13

Dear All, I have solved a complex structure of two proteins, and a reviewer has asked to compare the altered interface binding of one particular binding partner (protein2) in this complex to various other similar deposited PDBs through r.m.s.d. calculations and rotation/translation matrices. After aligning ~4 structures from the PDB (specifically aligning 1 chain to the other binding partner, protein1) to my structure, I want to calculated the rmsd before and after re-aligning the deposited structures (containing protein2) to my complexed protein2. I have used the superpose utility in phenix to align the C-alphas, however, I am getting very large rmsd values after alignment (~3.3). This is rather strange as the aligned proteins are essentially the exact same, both in sequence and secondary structure. Using various different programs such as SSM, Coot, and others give me an rmsd value of ~1, which is far more reasonable, but they do not output a "start" rmsd value. Any suggestions on what the cause of this large rmsd value? Or possibly another program that could provide start and final rmsd values along with rotation/translation matrices for alignment? Thanks, Bret

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links in phenix summary
by Christian Roth 03 Apr '13

03 Apr '13

Dear all, thanks to the phenix team which helped me a lot to resolve all issues regarding the correct link definitions. I have summarised a few things which one might consider if nonstandard links are necessary. Try phenix ready set to get your links out of the pdb. Do not forget to change the possible LINKR to LINK! Inspect the links and decide if they are useful! Peptide links are automatically incorporated if residues are close (inspect geo file) Non standard peptide links could be created using using an now available alpha release script: elbow.ligand_linking model.pdb Inspect the generated cif file and correct angles and incorporate dihedrals and so on if necessary. Sugar links which exists in the mon_lib.cif should be incorporated using the apply_cif link option like refinement.pdb_interpretation.apply_cif_link { data_link = ALPHA1-4 residue_selection_1 = chain B and resname GLC and resseq 1 residue_selection_2 = chain B and resname GLC and resseq 2 } According to the link definition the C1 oxygen of the following sugar with the higher number must be removed. The automatic incorporation of sugar links will be probably soon available in phenix. Nigel is already working on this. If one want use hydrogens in the refinement, they have to be added previously with ready_set and afterwards the OH4 sugar hydrogen has to be removed before the refinement. For links with symmetry related atoms the symmetry operator must be included in a custom bond definition efinement.geometry_restraints.edits { bond { action = *add delete change atom_selection_1 = chain A and resname HEM and resid 154 and name FE atom_selection_2 = chain A and resname MTO and resid 155 and name O symmetry_operation = -x,y,-z distance_ideal = 2.2 sigma = 0.01 } } The operator can be obtained using iotbx.show_distances your.pdb > all_distances Search for keyword "sym" or from Coot clicking on the symm option. Coot print out the operator and the translation term separately. Both has to be merged in the final operator used in phenix! Christian

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Fw:Dialing Pretty
by Dialing Pretty 03 Apr '13

03 Apr '13

http://www.riofoliashow.com/bhblnsv/jx.vohys?dwr Dialing Pretty gzdrrasz

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MR-Rosetta server?
by Mark J van Raaij 02 Apr '13

02 Apr '13

Dear All, for a recent dataset, I would like to try MR-Rosetta, as normal MR didn't work (not surprising perhaps, as the closest model is from NMR and with only about 20% sequence identity). Even though I don't think there is much chance of success, I would like to try MR-Rosetta anyway, although without having to install Rosetta if possible. Is there a server that would take care of the whole process? I.e. take the input mtz and the hopefully homologous structure supplied by me, and run Rosetta followed by MR in Phenix? In its defect, is there an online server that does the Rosetta part of MR-Rosetta, that would give a Rosetta-improved output model for putting into MR by Phenix, which I already have installed? Some side-ways related questions: - is it feasible to install Rosetta under MacOSX for a not very computer-literate user? - Phenix seems to slow down my MacPro a lot, even if I use just one of the 8 processors - is 4 Gb of RAM too little? Sorry for the rather rambling mail... Greetings, Mark Mark J van Raaij Lab 20B Dpto de Estructura de Macromoleculas Centro Nacional de Biotecnologia - CSIC c/Darwin 3 E-28049 Madrid, Spain tel. (+34) 91 585 4616 http://www.cnb.csic.es/~mjvanraaij

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.::Hexi Zhang::.
by Hexi Zhang 02 Apr '13

02 Apr '13

http://www.shoes4me.com/jpnnv/qkawwtmiigdaxdliiayzmr.opdpdklrvlts

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which monlib in refinement?
by Konrad Bergen 02 Apr '13

02 Apr '13

Hello phenixbb, i was recently refining a DCT and was a bit puzzled when i got outliers in torsion angles (readout from the final .geo file). The DCT was built in coot (using the ccp4 monomer library) and seems to fit these restraints. A closer look gave me a discrepancy in the torsion angles between the ccp4 (ver 6.3.0) and the corresponding phenix (dev1325) file /usr/local/ccp4-6.3.0/ccp4-6.3.0/lib/data/monomers/d/DCT.cif _chem_comp_tor.comp_id _chem_comp_tor.id _chem_comp_tor.atom_id_1 _chem_comp_tor.atom_id_2 _chem_comp_tor.atom_id_3 _chem_comp_tor.atom_id_4 _chem_comp_tor.value_angle _chem_comp_tor.value_angle_esd _chem_comp_tor.period DCT var_1 O3G PG O3B PB -60.011 20.000 1 DCT var_2 PG O3B PB O3A -179.960 20.000 1 DCT var_3 O3B PB O3A PA -179.992 20.000 1 DCT var_4 PB O3A PA "O5'" 179.964 20.000 1 DCT var_5 O3A PA "O5'" "C5'" 179.986 20.000 1 DCT var_6 PA "O5'" "C5'" "C4'" -179.998 20.000 1 DCT var_7 "O5'" "C5'" "C4'" "O4'" 65.696 20.000 3 DCT var_8 "C5'" "C4'" "C3'" "C2'" -150.000 20.000 3 DCT var_9 "C4'" "C3'" "C2'" "C1'" 30.000 20.000 3 DCT var_10 "C5'" "C4'" "O4'" "C1'" 150.000 20.000 1 DCT var_11 "C4'" "O4'" "C1'" N1 -150.000 20.000 1 DCT var_12 "O4'" "C1'" "C2'" "C3'" 0.000 20.000 3 DCT var_13 "O4'" "C1'" N1 C6 -121.764 20.000 1 DCT CONST_1 "C1'" N1 C2 N3 180.000 0.000 0 DCT CONST_2 "C1'" N1 C6 C5 180.000 0.000 0 DCT CONST_3 N1 C6 C5 C4 0.000 0.000 0 DCT CONST_4 C6 C5 C4 N3 0.000 0.000 0 DCT CONST_5 C5 C4 N4 HN41 179.773 0.000 0 DCT CONST_6 C5 C4 N3 C2 0.000 0.000 0 DCT CONST_7 C4 N3 C2 O2 180.000 0.000 0 /usr/local/phenix.test/latest/chem_data/mon_lib/d/DCT.cif _chem_comp_tor.comp_id _chem_comp_tor.id _chem_comp_tor.atom_id_1 _chem_comp_tor.atom_id_2 _chem_comp_tor.atom_id_3 _chem_comp_tor.atom_id_4 _chem_comp_tor.value_angle _chem_comp_tor.value_angle_esd _chem_comp_tor.period DCT var_3 O1G PG O3B PB 2.570 20.000 1 DCT var_4 PG O3B PB O3A 83.412 20.000 1 DCT var_6 O3B PB O3A PA -132.456 20.000 1 DCT var_7 PB O3A PA O5* -51.566 20.000 1 DCT var_9 O3A PA O5* C5* -166.199 20.000 1 DCT var_10 PA O5* C5* C4* 135.553 20.000 1 DCT var_11 O5* C5* C4* C3* 12.096 20.000 3 DCT var_12 C5* C4* O4* C1* 143.686 20.000 1 DCT var_13 C5* C4* C3* C2* -117.819 20.000 3 DCT var_14 C4* C3* C2* C1* -21.471 20.000 3 DCT var_15 C3* C2* C1* N1 150.776 20.000 3 DCT var_16 C3* C2* C1* O4* 32.781 20.000 3 DCT var_17 C2* C1* N1 C2 121.270 20.000 1 DCT var_18 C2* C1* N1 C6 -65.572 20.000 1 DCT CONST_1 C1* N1 C2 N3 180.000 0.000 0 DCT CONST_2 N1 C2 N3 C4 0.000 0.000 0 DCT CONST_3 C2 N3 C4 C5 0.000 0.000 0 DCT var_19 N3 C4 N4 HN41 0.000 20.000 1 DCT CONST_4 N3 C4 C5 C6 0.000 0.000 0 DCT CONST_5 C4 C5 C6 N1 0.000 0.000 0 I am just wondering which values/library to use or if i got something completely wrong. Best regards Konrad

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2nd announcement: 2013 workshop on Neutron Scattering Applications in Structural Biology
by Meilleur, Flora 02 Apr '13

02 Apr '13

4th Workshop on Neutron Scattering Applications in Structural Biology Oak Ridge, TN (USA). June 24 – June 28, 2013 Application deadline: April 22, 2013 No registration fee. Travel and accommodation grants available for participants from U.S. institutions. Detailed information available at: http://neutrons.ornl.gov/conf/gcnb2013/ Best Regards, Flora Meilleur, Ph. D Assistant Professor, Molecular and Structural Biochemistry North Carolina State University Neutron Sciences Directorate Oak Ridge National Laboratory Phone: 865-242-5747

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Fitting ligand using coot
by bsubedi＠btk.fi 31 Mar '13

31 Mar '13

Hi all, I tried to fit the ligand using the coot -> calculate-> other modeling tools-> Find ligands. I have imported cif to coot and also opened the pdb file of my ligand. However, coot do not identify the ligand and asks to adjust r.m.s.d. I can see the density for my ligand. Could anyone suggest me what could be the problem or if I am missing anything here. Best regards. Bishwa

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Re: [phenixbb] question about FFT map coefficients
by Michael Thompson 29 Mar '13

29 Mar '13

Hi Nat, The FFT didn't work out, but I'm not sure if it's due to negative Fs. When I set up the FFT map coefficients utility with my mtz file, after picking my input I get a warning that "The reflections file does not appear to contain any suitable map coefficients." Then if I try to run it anyway I get the error message "There are no map coefficients in this MTZ file." An mtz dump confirms that I have columns FP and SIGFP. Additional info: these Fs were generated using a python script that I wrote, and there are not meaningful values for SIGFP. My script simply wrote out 0.000 to the SIGFP column for each reflection essentially as a place holder. I thought that maybe 0 was not a valid entry for SIGFP so I changed it to 0.001 so there would be some value there, but I get all the same errors. Could this be the problem? Any suggestions? Thanks for the help. Sorry to bug you. Mike ----- Original Message ----- From: "Nathaniel Echols" <nechols(a)lbl.gov> To: "PHENIX user mailing list" <phenixbb(a)phenix-online.org> Sent: Thursday, March 28, 2013 3:42:31 PM GMT -08:00 US/Canada Pacific Subject: Re: [phenixbb] question about FFT map coefficients On Thu, Mar 28, 2013 at 3:28 PM, Michael Thompson <miket(a)chem.ucla.edu> wrote: > I have an mtz file with map coefficients that are essentially Fo-Fo for two data sets. I would like to generate a map using these coefficients, but because the subtraction of Fs has already been done, there are some values of FP that are negative. Is "FFT map coefficients" able to handle negative values for FP? My guess would be that the answer is yes, because internally the amplitudes and phases for map calculation are combined to form a single array of complex numbers, and this effectively converts the amplitudes to be all-positive. Also, if this were not the case, the isomorphous or anomalous difference maps would never work. But I haven't actually tried what you're wanting to do with real data - if the result isn't what you expect, let us know. -Nat _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://phenix-online.org/mailman/listinfo/phenixbb -- Michael C. Thompson Graduate Student Biochemistry & Molecular Biology Division Department of Chemistry & Biochemistry University of California, Los Angeles miket(a)chem.ucla.edu

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question about FFT map coefficients
by Michael Thompson 28 Mar '13

28 Mar '13

Hello All, A quick question about the "FFT map coefficients" utility in the GUI: I have an mtz file with map coefficients that are essentially Fo-Fo for two data sets. I would like to generate a map using these coefficients, but because the subtraction of Fs has already been done, there are some values of FP that are negative. Is "FFT map coefficients" able to handle negative values for FP? If not, I can always change the sign of negative Fs and add 180 to the corresponding model phases, but I was hoping I could avoid this. Thanks in advance for the help! Mike P.S. I do know there is an Fo-Fo map option in phenix, but the origin of my map coefficients is more complicated than simply Fo-Fo, so I cannot use this option. -- Michael C. Thompson Graduate Student Biochemistry & Molecular Biology Division Department of Chemistry & Biochemistry University of California, Los Angeles miket(a)chem.ucla.edu

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