Hello phenix users, I am wondering if phenix.elbow can attach H onto phosphate group for refinement. The reason for that, based on different pH environment, phosphate group should have different charges with respect to how many protons attached. In addition, how can I know normal distance restraints such as ATP? What I only know from the coot is that it shows P-O bond length is 1.61A and P-O bond (delocalized double bond) is 1.5A. The reason for this is, I heard about phosphate ion, if it is protonated, then the bond length of HO-P is longer than that of non-protonated O-P. I want to try if is true for ATP as well. Is there anyone who knows practically testing this fact by using phenix? Thanks in advance, YoungJin
Hi YoungJin, The elbow author, Nigel, is out of email reach this week and next. In the meantime I'll offer what I know...
I am wondering if phenix.elbow can attach H onto phosphate group for refinement. The reason for that, based on different pH environment, phosphate group should have different charges with respect to how many protons attached.
You can try out elbow's capabilities like this: phenix.elbow --key atp --opt Note that you get a slightly different result each time you run it; you may want to try a few runs and compare.
In addition, how can I know normal distance restraints such as ATP?
You can find the ATP restraints definitions like this: phenix.where_mon_lib_list_cif cd <what you see minus the last two components of the path> cd a more ATP.cif If you run phenix.refine, you can inspect the restraints used by looking at the .geo file.
What I only know from the coot is that it shows P-O bond length is 1.61A and P-O bond (delocalized double bond) is 1.5A.
I'm not sure if eblow handles the delocalization. You could run elbow for your molecule to get a starting .cif file, then modify manually following the standard ATP.cif file. Ralf
Dear Friends, Does anyone have experience of building dna in coot? I can see the clear density, but I need to move some nucleotides. Any suggestion/direction is wellcome. Thanking you in advance... Raja
Raja Dey wrote:
Dear Friends,
Does anyone have experience of building dna in coot? I can see the clear density, but I need to move some nucleotides. Any suggestion/direction is welcome.
Dear Raja, (Not that I've done a lot of this you understand) but what you need to do depends on how bad your model is (and how good your map is). If it's close you can simply click and drag around a residue range (more than 3 residues takes some experience to handle correctly (generally I don't do that)). If the model is a long way off, I'd delete the bits that don't fit to density - and build off a well-fitting stump using add terminal residue and simple mutate (and then refine). And repeat. You might find the Watson-Crick Base Pair tool useful. HTH, Paul.
Dear Paul,
Could you please tell me how I can drug 1 or 2 nucleotide at a time? Do I need to create a fragment? Can I do real space refine for nucleotide?
I also have a basic question? When I am using 'Auto open mtz' under file to open *_map_coeffs.mtz created in phenix I am getting two different colored maps for 'FOFCWT PHFOFC'. Which one is what? Are they (+ve) and (-ve) sigma level?
Thanks for your help.
Regards...
Raja
R
----- Original Message -----
From: Paul Emsley
Raja Dey wrote:
Dear Friends,
Does anyone have experience of building dna in coot? I can see the clear density, but I need to move some nucleotides. Any suggestion/direction is welcome.
Dear Raja,
(Not that I've done a lot of this you understand) but what you need to do depends on how bad your model is (and how good your map is). If it's close you can simply click and drag around a residue range (more than 3 residues takes some experience to handle correctly (generally I don't do that)).
If the model is a long way off, I'd delete the bits that don't fit to density - and build off a well-fitting stump using add terminal residue and simple mutate (and then refine). And repeat.
You might find the Watson-Crick Base Pair tool useful.
HTH,
Paul. _______________________________________________ phenixbb mailing list [email protected] http://www.phenix-online.org/mailman/listinfo/phenixbb
Hi Raja,
I also have a basic question? When I am using 'Auto open mtz' under file to open *_map_coeffs.mtz created in phenix I am getting two different colored maps for 'FOFCWT PHFOFC'. Which one is what? Are they (+ve) and (-ve) sigma level?
FoFCWT is the amplitude and PHFOFC is the phase of the FOFC map. If you want to open the 2FOFC click on the corresponding amplitudes and phases. FoFC is colored in green (+ve density) and red (-ve density. You can change the colors in coot. Shya
Dear Paul, Could you please tell me how I can drug 1 or 2 nucleotide at a time? Do I need to create a fragment? Can I do real space refine for nucleotide?
I also have a basic question? When I am using 'Auto open mtz' under file to open *_map_coeffs.mtz created in phenix I am getting two different colored maps for 'FOFCWT PHFOFC'. Which one is what? Are they (+ve) and (-ve) sigma level? Thanks for your help. Regards... Raja
R
----- Original Message ----- From: Paul Emsley
Date: Tuesday, May 19, 2009 3:39 pm Subject: Re: [phenixbb] building dna in coot To: PHENIX user mailing list Raja Dey wrote:
Dear Friends,
Does anyone have experience of building dna in coot? I can see the clear density, but I need to move some nucleotides. Any suggestion/direction is welcome.
Dear Raja,
(Not that I've done a lot of this you understand) but what you need to do depends on how bad your model is (and how good your map is). If it's close you can simply click and drag around a residue range (more than 3 residues takes some experience to handle correctly (generally I don't do that)).
If the model is a long way off, I'd delete the bits that don't fit to density - and build off a well-fitting stump using add terminal residue and simple mutate (and then refine). And repeat.
You might find the Watson-Crick Base Pair tool useful.
HTH,
Paul. _______________________________________________ phenixbb mailing list [email protected] http://www.phenix-online.org/mailman/listinfo/phenixbb
_______________________________________________ phenixbb mailing list [email protected] http://www.phenix-online.org/mailman/listinfo/phenixbb
Dear Raja, At the risk of straying off topic.. Raja Dey wrote:
Could you please tell me how I can drag 1 or 2 nucleotide at a time? Oh dear - slightly worrying question. Click the refine icon then click on each of residues you wish to move.
Do I need to create a fragment?
No.
Can I do real space refine for nucleotide?
Nucleotides - Yes. If you wish to pursue this thread, let's do it privately or somewhere other than the phenixbb (I fear that too much of this sort of stuff will be disapproved of). Cheers, Paul.
Hi Young-Jin, why don't you try two refinement runs using two different CIF files for ATP where different P-O bond lengths are defined (just edit CIF files manually): phenix.refine model.pdb data.mtz atp_1.cif output.prefix=atp_1 phenix.refine model.pdb data.mtz atp_2.cif output.prefix=atp_2 ? Then see which one produces a better result locally (R-factors will not show this). If you don't see any difference than the resolution or/and data quality do not allow distinguishing this level of detail. Pavel. On 5/19/09 8:42 AM, Young-Jin Cho wrote:
Hello phenix users,
I am wondering if phenix.elbow can attach H onto phosphate group for refinement. The reason for that, based on different pH environment, phosphate group should have different charges with respect to how many protons attached.
In addition, how can I know normal distance restraints such as ATP? What I only know from the coot is that it shows P-O bond length is 1.61A and P-O bond (delocalized double bond) is 1.5A. The reason for this is, I heard about phosphate ion, if it is protonated, then the bond length of HO-P is longer than that of non-protonated O-P. I want to try if is true for ATP as well. Is there anyone who knows practically testing this fact by using phenix?
Thanks in advance,
YoungJin
_______________________________________________ phenixbb mailing list [email protected] http://www.phenix-online.org/mailman/listinfo/phenixbb
participants (6)
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Paul Emsley
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Pavel Afonine
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Raja Dey
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Ralf W. Grosse-Kunstleve
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sbiswas2@ncsu.edu
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Young-Jin Cho