Sorry for suggesting something you might have checked already, but are
you sure you cannot simply do a 'peptide flip' and get a nice
hydrogen bond between the amide nitrogen of the main chain and the
aspartate in question? Such flips can at times be less than
obvious, especially if resolution is 2.5 or worse, and its best to
rule them 100% out before discussing this strange
(but possible under some conditions) hydrogen bond.
Tassos
On Apr 26, 2009, at 14:50, b...@freesurf.fr wrote:
Hi Frank,
such interactions are certainly possible, in particular if additional
H-bonding side chains are available to stabilize the arrangement.
I'm not
aware of any examples involving main chain carbonyls, but for a
discussion
of carbonyl-carbonyl side chain interactions see the following paper:
Flocco, M.M. and Mowbray, S.L. (1995) Strange Bedfellows: Interactions
between Acidic Side-Chains in Proteins, J. Mol. Biol. 254 96-105
Best wishes, Sebastiaan Werten.
----- Original Message -----
From: Frank Lee
To: CCP4BB@JISCMAIL.AC.UK
Sent: Saturday, April 25, 2009 7:47 AM
Subject: [ccp4bb] hydrogen bond between aspartate side chain and main
chain carbonyl group?
Hi,
In a new structure we observed a hydrogen bond between an aspartate
side
chain and a main chain carbonyl group. Because both of them are
electronegative, I am puzzled.
My questions are: does this hydrogen bond make sense at all? any
precedent
for such a hydrogen bond?
I would appreciate your help very much!
Frank
P please don't print this e-mail unless you really need to
Anastassis (Tassos) Perrakis, Principal Investigator / Staff Member
Department of Biochemistry (B8)
Netherlands Cancer Institute,
Dept. B8, 1066 CX Amsterdam, The Netherlands
Tel: +31 20 512 1951 Fax: +31 20 512 1954 Mobile / SMS: +31 6 28 597791
