And if you liked SPASM, you'll love the SPASM web-server that Mark Harris has made:

           http://eds.bmc.uu.se/eds/spana.php?spasm

The decapeptide search is similar to the quest for left-handed helices described in the original publication.

Recipe:

- from the start page, upload a small PDB file that only contains your decapeptide

- on the parameters page, use:
  - large database to search in
- screen on CA atoms only (you're only interested in the backbone conformation, not the sequence or sidechains)
  - finer screening on backbone atoms only
- you can leave the other parameters as they are by default (if you expect many hits, which slows everything down, you can reduce the RMSD cut-off initially, e.g. to 0.5 A)

- start the search

- this will typically take 1-5 minutes

- the hits (if any) are presented on the results page and from there you can quickly explore them, download them or visualise any or all of them with Jmol


--Gerard






On Tue, 15 Dec 2009, MARTYN SYMMONS wrote:

I think SPASM by Gerard Kleywegt is a great tool for this sort of thing - you 
can set the similarity matrix threshold to make it more or less sequence 
independent (it still calculates the sequence match which is good for looking 
for key residues in the motif like structurally required GLYs). You can also 
restrict it to just CA positions. And you can set the thresholds for the search 
to narrow down on the basis of rmsd.

J Mol Biol. 1999 Jan 29;285(4):1887-97.
Recognition of spatial motifs in protein structures.
Kleywegt GJ.

You can download the program and a search library - currently july 2008 pdb I 
think (culled to 99% seq ident. is the best one). But could be something more 
recent available?

Good luck
Martyn

Martyn Symmons - Cambridge
________________________________
From: Patrick Loll <pat.l...@drexel.edu>
To: CCP4BB@JISCMAIL.AC.UK
Sent: Monday, 14 December, 2009 20:02:53
Subject: [ccp4bb] 3D search for peptide conformers?

I have a 10-residue stretch of a protein that adopts an interesting conformation; I'd like to know if this conformation occurs in other proteins. I'd welcome suggestions for tools that will allow me to to search for this peptide conformation in the PDB. I naturally thought of DALI, but it seems to require a minimum length of 30 residues.
Thanks,

Pat

---------------------------------------------------------------------------------------
Patrick J. Loll, Ph. D. Professor of Biochemistry & Molecular Biology
Director, Biochemistry Graduate Program
Drexel University College of Medicine
Room 10-102 New College Building
245 N. 15th St., Mailstop 497
Philadelphia, PA  19102-1192  USA

(215) 762-7706
pat.l...@drexelmed.edu



Best wishes,

--Gerard

******************************************************************
                           Gerard J.  Kleywegt
   Dept. of Cell & Molecular Biology  University of Uppsala
                   Biomedical Centre  Box 596
                   SE-751 24 Uppsala  SWEDEN

    http://xray.bmc.uu.se/gerard/  mailto:ger...@xray.bmc.uu.se
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   The opinions in this message are fictional.  Any similarity
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