"James O. McInerney PhD" <j.mcinerney at nhm.ac.uk> writes:
>As far as I remember, proline is generally used more frequently in
>proteins from thermophiles than in proteins from mesophiles. Does
>anybody have a definitive reference for this?
We've measured the frequency of all residues in proteins in
Methanococcus jannaschii (a thermophilic archaeon), several other
organisms whose whole or mostly-complete genomes are available, and
the owl non-redundant protein database. In terms of proline fraction,
M. jannaschii falls near the bottom of the lot, though one organism
had less.
That said, several studies have found additional prolines in
particular proteins of interest. I've seen a poster from Yigal
Bernstein's lab at the Weizmann institute which showed a dramatic
increase in prolines from mesophilic to thermophilic homologs of the
same protein. There are some papers which have noted less dramatic
effects--I can probably dig these up. However, the most common
feature mentioned about thermophilic proteins is the networks of
salt-bridges which they form.
Hope this helps.
Best regards,
Steve Brenner
--
Steven E. Brenner | S.E.Brenner at bioc.cam.ac.uk
MRC Laboratory of Molecular Biology |
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