[bionet.software] Explore

lloyd@bruce.cs.monash.OZ.AU (lloyd allison) (09/27/90)

This is to request references to a package called Explore (sp?)
that predicts protein tertiary structure.

Lloyd Allison 		
Department of Computer Science	UUCP:	lloyd@bruce.cs.monash.edu.au
Monash University, Clayton	or  :   uunet!munnari!bruce.cs.monash.edu!lloyd
VICTORIA 3168, AUSTRALIA        Tel :   565-5205            FAX: +61 3 565 5146

usenet@nlm.nih.gov (usenet news poster) (09/27/90)

In article <3137@bruce.cs.monash.OZ.AU> lloyd@bruce.cs.monash.OZ.AU (lloyd allison) writes:
>This is to request references to a package called Explore (sp?)
>that predicts protein tertiary structure.
>
>Lloyd Allison 		
>Department of Computer Science	UUCP:	lloyd@bruce.cs.monash.edu.au
>Monash University, Clayton	or  :   uunet!munnari!bruce.cs.monash.edu!lloyd
>VICTORIA 3168, AUSTRALIA        Tel :   565-5205            FAX: +61 3 565 5146

EXPLOR is a Polygen product based on work by Axel Brunger and Martin Karplus
using molecular dynamics and simulated annealing to refine three dimensional
X-ray crystal structures.

See:

Brunger AT; Clore GM; Gronenborn AM; Karplus M
Proc Natl Acad Sci U S A 83: 3801-5 (1986)
Three-dimensional structure of proteins determined by molecular
    dynamics with interproton distance restraints: application to crambin.

and many subsequent references.

David States					states@ncbi.nlm.nih.gov
National Center for Biotechnology Information
National Library of Medicine

Cherry@Coffee.MGH.Harvard.EDU (J. Michael Cherry) (09/27/90)

In article <3137@bruce.cs.monash.OZ.AU> lloyd@bruce.cs.monash.OZ.AU (lloyd 
allison) writes:
> This is to request references to a package called Explore (sp?)
> that predicts protein tertiary structure.
> 
> Lloyd Allison           
> Department of Computer Science  UUCP:   lloyd@bruce.cs.monash.edu.au

Sounds like you are referring to a program originally from Axel Brunger
while at Harvard, now at U of Chicago I believe.  See A.  Brunger, Acta
Cryst.  A, A46, 46-57 (1990).  This program like other programs from
Karplus' group at Harvard are commercialized by Polygen Corp in Waltham,
Massachusetts (617) 890-2888.  The introduction on the X-PLOR product
sheet says:

"X-PLOR (tm) is a macromolecular crystal structure program
which integrates x-ray diffraction data with molecular
mechanics, dynamics, energy minimization, or NMR internuclear
distances to aid in the solution of 3-dimensional molecular
structures. The technique of simulated annealing overcomes
local misplacement of flexible fragments. X-PLOR uses the
CHARMm (tm) force field, modified automatically for use in
high temperature dynamics simulations. The QUANTA (tm) 
Structure Analysis and Refinement modeling application
package facilitates access to and data exchange between
X-PLOR and QUANTA."

X-PLOR is not meant to generate a folded protein structure from just the
primary amino acid sequence. It requires structural data like an electron
density map or NMR measurements as its reference. It then manipulates the
coordinates to fit the structural data, as opposed to CHARMm which is 
generally used to fit structures to an energy function.

I have no connection to Polygen Corp. I am not even a satisfied user.

Mike Cherry
cherry@frodo.mgh.harvard.edu
Department of Molecular Biology
Massachusetts General Hospital, Boston