Re: [ccp4bb] secondary structure restraints [was: Phenix version 1.6.1 released]

2010-03-31 Thread Nathaniel Echols
On Wed, Mar 31, 2010 at 8:47 AM, Dirk Kostrewa kostr...@genzentrum.lmu.dewrote: this is very interesting! From the list of changes, it appears that in version 1.6.1, you use a similar idea to implement hydrogen bonds via DSSP during refinement that I used to stabilize the 4.3 A refinement of

Re: [ccp4bb] Secondary structure restraints

2009-01-12 Thread Pete Meyer
to my knowledge, none of the existing reciprocal-space refinement programs is really suitable for low-resolution refinement. In my For what it's worth, I've had good luck with refmac5D, which incorporates an SAS target into model refinement (I believe this was has now been incorporated into the

Re: [ccp4bb] Secondary structure restraints

2009-01-09 Thread Dirk Kostrewa
Dear Phil CCP4ers, to my knowledge, none of the existing reciprocal-space refinement programs is really suitable for low-resolution refinement. In my opinion, what is clearly missing, are automatic hydrogen-bond- restraints that would stabilize all secondary structures and other

Re: [ccp4bb] Secondary structure restraints

2009-01-09 Thread Eleanor Dodson
Phil Evans wrote: Does anyone have a good way of imposing secondary structure restraints in a low resolution refinement? I've done this in the past as hydrogen bond distance restraints within helices, input to refmac as LINKs , with the list generated with a little program and certain amount

[ccp4bb] Secondary structure restraints

2009-01-08 Thread Phil Evans
Does anyone have a good way of imposing secondary structure restraints in a low resolution refinement? I've done this in the past as hydrogen bond distance restraints within helices, input to refmac as LINKs , with the list generated with a little program and certain amount of pain

Re: [ccp4bb] Secondary structure restraints

2009-01-08 Thread Eckhard Hofmann
XPLO2D from the USF-Suite does this: snippet from manual You feed it a PDB file of the model to which you want to restrain your refinement model (e.g., that high-resolution native structure you already have, even though it may be in a different spacegroup or with different domain

Re: [ccp4bb] Secondary structure restraints: Oops

2009-01-08 Thread Eckhard Hofmann
Hi Phil, sorry, haven't read you question properly. No idea how to get easily from top/par to cif for refmac. Probably would need a little scripting, but that's been exactly your question ... Eckhard XPLO2D from the USF-Suite does this: snippet from manual You feed it a PDB file of the

Re: [ccp4bb] Secondary structure restraints: Oops

2009-01-08 Thread Garib Murshudov
If top/par file could be converted to the following type of instructions then you do not need to define everything in cif file (these are for torsion angles, all other restraints can be defined similarly) General torsion angle restraints for any quartet of atoms: external torsion first

Re: [ccp4bb] Secondary structure restraints: Oops

2009-01-08 Thread Phil Evans
I would guess that it would be easier to restrain a helix by hydrogen bond lengths rather than by phi/psi torsion angles, and that could work for sheets as well. Phil On 8 Jan 2009, at 19:05, Garib Murshudov wrote: If top/par file could be converted to the following type of instructions

Re: [ccp4bb] Secondary structure restraints

2009-01-08 Thread Sean Johnson
Phil, I have a student who has been working on a python script that will allow the user to manually define hydrogen bonds in pymol (i.e. click on the nitrogen and oxygen atoms that you want to restrain). It then outputs a restraints definition file for refinement in phenix. It can be tedious

Re: [ccp4bb] Secondary structure restraints

2009-01-08 Thread Paul Paukstelis
I put together a simple perl script to take WHATIF optimal hydrogen bonds from a known structure and generate refmac or cns restraints. You can limit it to backbone or all h-bonds. Refmac: http://hood.icmb.utexas.edu/~paul/ccp4_hbond CNS: http://hood.icmb.utexas.edu/~paul/cns_hbond Phil Evans

[ccp4bb] secondary structure restraints

2008-02-13 Thread Sean Johnson
I am trying to build and refine a model into 3.6 angstrom Se-met phased maps. What is the best way to define secondary structure restraints for refinement? (hydrogen bonds? backbone torsion angles?) Are there any tools available to help me define restraints for a specified region, or do I

Re: [ccp4bb] secondary structure restraints

2008-02-13 Thread Raji Edayathumangalam
] To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] secondary structure restraints I am trying to build and refine a model into 3.6 angstrom Se-met phased maps. What is the best way to define secondary structure restraints for refinement? (hydrogen bonds? backbone torsion angles?) Are there any tools

Re: [ccp4bb] secondary structure restraints

2008-02-13 Thread Paul Paukstelis
For a (very) low resolution RNA/protein complex in which we had high(er) resolution structures for both components, I used the optimal hydrogen bonds from these structures (WHATIF output) as restraints. I made a couple perl scripts to take this output and generated either CNS or REFMAC