Re: [ccp4bb] expression vector

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CCP4bb <-- 2008 <-- March 2008 <-- 27 March 2008

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Subject: Re: Pointless 1.2.15 and ccp4i
From: Andrew Purkiss-Trew a {- dot -} purkiss {- at -} MAIL {- dot -} CRYST {- dot -} BBK {- dot -} AC {- dot -} UK
Date: 2008-03-27

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Subject: Re: expression vector
From: junfeng liu jliu {- at -} NIMR {- dot -} MRC {- dot -} AC {- dot -} UK
Date: 2008-03-27

Subject: Re: expression vector
From: Miles Pufall mpufall {- at -} CMP {- dot -} UCSF {- dot -} EDU
Date: 2008-03-27

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:
> ÑîÁøÇà 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
>>
>> ------------------------------------------------------------------------
>> Ê¹ÓÃÐÂÒ»´ú Windows Live Messenger ÇáËÉ½»Á÷ºÍ¹²Ïí£¡ Á¢¼´ÌåÑé£¡
>>
> 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: rrowlett@mail.colgate.edu

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

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CCP4bb <-- 2008 <-- March 2008 <-- 27 March 2008

Previous message:
Subject: Re: Pointless 1.2.15 and ccp4i
From: Andrew Purkiss-Trew a {- dot -} purkiss {- at -} MAIL {- dot -} CRYST {- dot -} BBK {- dot -} AC {- dot -} UK
Date: 2008-03-27

Next message:
Subject: Re: expression vector
From: junfeng liu jliu {- at -} NIMR {- dot -} MRC {- dot -} AC {- dot -} UK
Date: 2008-03-27