Feb 21, 1993	       HELIXVU--A program for analyzing DNA footprint data

   HELIXVU illustrates an 80 bp region of DNA as a helix (sliced lengthwise
and folded out flat) with the sequence listing printed above the helix
diagram.  This view of the helix is useful for viewing footprint data to 
see the spatial relationship between DNA modifications.  
   Modification symbols (opened or closed circles or squares, opened
triangles, or carats) may be assigned to any base.  Symbols can be drawn
above and/or below the sequence listing (for the Forward and Reverse
strands, respectively) or on the helix.  Modifications shown on the helix
may be assigned to the DNA backbone, the major groove, and/or the minor
groove.  This view enables the identification of faces of the helix
that are affected by the DNA modification agent.  

The file HELIXVU.ZIP  includes two compressed files:

HELIXVU.EXE--the executable program file, all that's needed to run the program.
HELIXVU.BAS--the source code which can be modified to customize HELIXVU.

   Documented QuickBASIC source code is included in the .ZIP file and may be 
altered to customize HELIXVU so that the program may recognize sequences
from other formats, print to different devices, or support more extensive
error checking.  The source code can run on the QBASIC interpreter included
with DOS 5.0.  HELIXVU was written as a simple tool to be used at our site.
While effective, it is a bit rudimentary.  However, many enhancements require
only a modest understanding of BASIC.  From time to time, I may be adding
features, as they become useful at our site, and I will make them available.
Look for PCL5 (LaserJet III and 4) support soon.
   The compiled version can output the graphical view that it creates to
an EGA or better screen.  Additionally, the program can send plotting
instructions in Hewlett-Packard Graphics Language to a plotter attached to
COM1:, COM2:, or to a file.  The input sequence must be from a GCG
formatted sequence file or a file created with HELIXVU (these normally have
the extension .HLX).

Questions or comments about HELIXVU can be sent to Richard Seyler,
BIOBN968@EMUVM1 bitnet.

The paper mail address is 3010 Rollins Research Center, Emory University,
Atlanta, GA 30322