I agree with Roger - provided, of course, that the same protein is
expressed from either vector with no extra amino acids at either end.
Quite often vectors include extra sequence at the N or C terminus that
are remnants of regions or linkers between the protein and
purification tags. There are definitely cases where a few amino acids
can make all the difference in crystallization. In addition there are
vectors that contain solubility tags that, if they are not removed,
might seriously impede crystallization.
You seem lucky, though, since both versions crystallize. Good for you!
Miles
On Mar 27, 2008, at 7:55 AM, Roger Rowlett wrote:
杨柳青 wrote: polylinker
Hello,everyone!
I have a question,is the expression vector effect crystallization
much?
For example,"PQE2-protein" structure has 2 molecules in one
unit-cell,"PQE70-protein single mutant" has 5molecules in one
unit-cell.Is the vector effect the results or the mutant itself?
Can protein with some kind vector does not produce crystals?
Thank you very much!
Best wishes!
liuqing
------------------------------------------------------------------------
使用新一代 Windows Live Messenger 轻松交流和共享！ 立即体验！
<http://messenger.live.cn/>
The expression vector is essentially irrelevant to protein
crystallization, as it is only the means by which the recombinant
protein is produced. However, the protein structure does have
everything
to do with crystallization conditions and results. Single amino acid
mutations, or the presence of purification tags, can have profound
effects on the unit cell symmetry and size of protein crystals. In
addition, a single protein can, and often does, crystallize under
different crystallization conditions in wildly different space groups
and asymmetric units.
--
------------------------------------------------------------------------
Roger S. Rowlett
Professor
Colgate University Presidential Scholar
Department of Chemistry
Colgate University
13 Oak Drive
Hamilton, NY 13346
tel: (315)-228-7245
ofc: (315)-228-7395
fax: (315)-228-7935
email: [EMAIL PROTECTED]
Miles Pufall
Postdoctoral Scholar
Yamamoto Lab
UC San Francisco
Cellular and Molecular Pharmacology
Mail Stop 2280
600 16th Street, Genentech Hall S-574
San Francisco, California 94158-2517
(415)476-4480
