Sat. Sept. 22nd, 2012
EBI
Good evening,
N-methyl-Pro is a known protein modification.
Was observed in Histone H2B from Drosophila for example. UniProt P02283
indicates that PTM Methylation at Pro-2 increases upon heat shock
The source (specie) and the conditions the protein were expressed in are
important.
The best DB for Protein modification is the RESID
http://www.ebi.ac.uk/RESID/
the entry is AA0419
Hope this help
Miri Hirshberg PDBe
p.s. PDB used to have a chem_comp dictionary entry for
this modification, PKR, now obsoleted.
On Sat, 22 Sep 2012, Nicholas M Glykos wrote:
Dear All,
We have a structure at its final stages of refinement (R~0.215,
Rfree~0.235) whose 1.9A 2mFo-DFc and mFo-DFc maps are a pleasure to have
and to share, with the notable exception of a 'feature' present on one of
the prolines:
https://dl.dropbox.com/u/11392126/alpha-Me-proline.jpg
[the positive (green) contour of the difference map stands at a hefty 5
sigma above mean]. It looks as if this is an alpha-Methyl-L-Proline but my
attempts to locate natural occurences of this modification in proteins
have all failed. Any ideas or suggestions or pointers ?
All the best,
Nicholas
--
Nicholas M. Glykos, Department of Molecular Biology
and Genetics, Democritus University of Thrace, University Campus,
Dragana, 68100 Alexandroupolis, Greece, Tel/Fax (office) +302551030620,
Ext.77620, Tel (lab) +302551030615, http://utopia.duth.gr/~glykos/
