Molecular Replacement Problem

[Steffen Graether]

I am engaged in co-crystallization of a protein with an inhibitor in
which the molecule weighs ~300. The starting model is the identical
protein structure at 2.3A. By using AMORE molecular replacement, the
rotation results are

	1.10	91.40	-0.42	0.0000	0.0000	0.0000	10.0 0.0
	166.50	136.22	54.00	0.0000	0.0000	0.0000	 7.9 0.0
	52.36	164.95	42.53	0.0000	0.0000	0.0000	 7.0 0.0

the translation results are
	1.10	91.40	-0.42	0.2900	0.2600	0.1981	28.8 50.6
	166.50	136.22	54.00	0.3206	0.3852	0.1630	18.5 54.1
	52.36	164.95	42.53	0.0029	0.2158	0.0223	28.3 55.3

and the fit function results are
-0.01 91.78 0.70 0.2873 0.2542 0.1999 12.1 55.1

It seems that the MR results are reasonable. I don't understand why
FItfun makes it worse. Any ideas would be much appreciated.

Thanks in advance.
e-mail: ye at crystal.biochem.queensu.ca