Uppsala Software News @ 960723
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                     ESSENS now available
                     ^^^^^^^^^^^^^^^^^^^^


The program ESSENS has been released today (as part of the RAVE
package).  ESSENS carries out real-space convolutions between
any type of (electron-density) map and any structural fragment.

This may sound boring, but what it boils down to is this:
with ESSENS you can detect the helices and strands in your
experimental map, prior to any map interpretation, skeletonisation,
or tracing !  (There are many other applications, but this is
most useful one for people attempting to interpret maps.)

The operation is simple: you feed the program a CCP4 map and
a structural fragment ("template"), submit two jobs (one for
finding the helices, the other for finding the strands), take
two days off, contour the two output "maps" and then either
throw a champagne party because you have "essens-ially" solved
your structure, or you go back to the lab bench and look for
more derivatives.

For more information (and before using the program), check out the
ESSENS manual at URL:

  http://onyx.bmc.uu.se/~gerard/manuals/essens_man.html

and a preprint of the paper describing the program (including some
GIF images of the results on real cases) at URL:

  http://onyx.bmc.uu.se/~gerard/essens/essens.html

(Both URLs are also accessible from the Uppsala Software Factory
page at URL: http://onyx.bmc.uu.se/~gerard/manuals/gerard_manuals.html)

Then download the appropriate RAVE version (if you are an academic user
or an industrial user with a RAVE license) from URL:

  ftp://rose.bmc.uu.se/pub/gerard/rave

The files are:
- rave_sgi.dirtar.Z   - executables for SGIs (NOT IRIX 6.2 !!!)
- rave_4dbig.dirtar.Z - ditto, but for larger maps (NOT IRIX 6.2 !!!)
- rave_esv.dirtar.Z   - executables for ESVs
- rave_alpha.dirtar.Z - executables for Dec Alphas running Dec Unix
- rave_virus.dirtar.Z - ditto, but for larger maps
- rave_doc.dirtar.Z   - documentation and example template files

The templates (for helices, strands, etc.) are also included in the
Web-version of the manual from which you can cut and paste them.

NOTE: the convolution is *very* slow.  Please read the manual for
      some hints as to how you can speed it up.

NOTE: if you have access to a Dec Alpha running Dec Unix, then this
      version is *strongly* recommended, since it blows away the
      SGI version (I haven't tried to optimise either version).
      I haven't even tried the ESV version ...

NOTE: an IRIX 6.2 version is expected soon.

If you use ESSENS, please quote:

  G J Kleywegt & T A Jones,
  Template convolution to enhance or detect structural
  features in macromolecular electron-density maps,
  Acta Cryst. D, in press (1996).

Have fun !

If you develop new templates that work well, or if you have suggestions
for improvements, please mailto:gerard@xray.bmc.uu.se !


--cd