very low B values

Ng ng at
Thu Aug 31 16:35:16 EST 1995

     Hello.  I am working with drug/DNA complexes.  A structure that I have
been working with has refined to an R of .17 and a free R of .25 with data
from 8 to 2.25 A.  However, with NUCLSQ (a nucleic acid variant of PROLSQ),
I have very low B values for many non-solvent atoms, with many as low as zero.
in XPLOR also gave me these low B values though XPLOR doesn't seem to allow
anything below 2.0.  I am at a loss to explain what is going on here.  Does
anyone have an idea?


Ho Leung Ng
University of California, Los Angeles
Molecular Biology Institute / School of Medicine
ng at

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