Dear Tiancen Hu:
Two things you need to do:
1. Try refining with cis-proline and see if it fits better.
2. Construct Fo-Fc and Fc-Fo maps (coot makes this very easy). See what they
are telling you.
Best of luck,
Bill Scott
On Thu, 18 Oct 2007 09:35:44 +0800
HTC <[EMAIL PROTECTED]> wrote:
Dear all,
Recently, I crystallized a mutant protein in which a Glycine was changed
to Proline. The resolution of the crystal is 3.35A. I performed molecular
replacement and refinement with CCP4. Surprisingly, no electronic density can
be detected for the side chain of Proline. Since Proline is always considered
rigid, I wonder if it is possible that this Proline is so flexible that its map
becomes undetectable? The density map is attached.
Thanks in advance!
Tiancen Hu
Shanghai Institute of Materia Medica
Rm. 2107, #555, ZuChongzhi Rd.
Shanghai 201203
P.R. China
