********> bugfix.74
Author:   Bill Ross and Tom Cheatham
Date:     8/5/96

Programs: Cornell et al. force field default cytosine residue geometries

Severity: Mild

Problem:  1) Cytosine H2'1 and H2'2 atoms have wrong positions in the 
	     template residue definitions.  This leads to incorrect placement 
	     when the templates are used to build residues from scratch or to 
	     replace missing atoms.

Fix:  Make the following changes to the amber41/dat/ file

	all_nuc94.in

      (or get a fresh copy from our web site: http://www.amber.ucsf.edu/amber/)
      then rebuild prep dbase db94.dat and remake leap libraries in 
      amber41/leap/lib/.
--------------------------------------------------------------------------------------
*** OLD all_nuc94.in
--- NEW all_nuc94.in
1520,1521c1520,1521
<   29   H2'1  HC    E   28  26   9    1.09    109.50   -200.00       0.0718
<   30   H2'2  HC    E   28  26   9    1.09    109.50   -320.00       0.0718
---
>   29   H2'1  HC    E   28  26   9    1.09    109.50    120.00       0.0718
>   30   H2'2  HC    E   28  26   9    1.09    109.50    240.00       0.0718
1580,1581c1580,1581
<   31   H2'1  HC    E   30  28  11    1.09    109.50   -200.00       0.0718
<   32   H2'2  HC    E   30  28  11    1.09    109.50   -320.00       0.0718
---
>   31   H2'1  HC    E   30  28  11    1.09    109.50    120.00       0.0718
>   32   H2'2  HC    E   30  28  11    1.09    109.50    240.00       0.0718
1640,1641c1640,1641
<   31   H2'1  HC    E   30  28  11    1.09    109.50   -200.00       0.0718
<   32   H2'2  HC    E   30  28  11    1.09    109.50   -320.00       0.0718
---
>   31   H2'1  HC    E   30  28  11    1.09    109.50    120.00       0.0718
>   32   H2'2  HC    E   30  28  11    1.09    109.50    240.00       0.0718
1700,1701c1700,1701
<   29   H2'1  HC    E   28  26   9    1.09    109.50   -200.00       0.0718
<   30   H2'2  HC    E   28  26   9    1.09    109.50   -320.00       0.0718
---
>   29   H2'1  HC    E   28  26   9    1.09    109.50    120.00       0.0718
>   30   H2'2  HC    E   28  26   9    1.09    109.50    240.00       0.0718
-----------------------------------------------------------------------------
Temporary workarounds: Supply all coords in PDB input file.

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