Re: [ccp4bb] The effect of His-tag location on crystallization
In trying to reproduce a very nice public structure a cloning mis-hap put a -GS- prior to the C-term 6His tag. The resultant crystals had a 500Ang C dimension and 16 molecules in the au. Even a single amino acid could make all the difference David Hargreaves Associate Principal Scientist _ AstraZeneca DECS, CPSS Mereside, 50F49, Alderley Park, Cheshire, SK10 4TF Tel +44 (0)01625 518521 Fax +44 (0) 1625 232693 David.Hargreaves @astrazeneca.com Please consider the environment before printing this e-mail -- AstraZeneca UK Limited is a company incorporated in England and Wales with registered number: 03674842 and a registered office at 2 Kingdom Street, London, W2 6BD. Confidentiality Notice: This message is private and may contain confidential, proprietary and legally privileged information. If you have received this message in error, please notify us and remove it from your system and note that you must not copy, distribute or take any action in reliance on it. Any unauthorised use or disclosure of the contents of this message is not permitted and may be unlawful. Disclaimer: Email messages may be subject to delays, interception, non-delivery and unauthorised alterations. Therefore, information expressed in this message is not given or endorsed by AstraZeneca UK Limited unless otherwise notified by an authorised representative independent of this message. No contractual relationship is created by this message by any person unless specifically indicated by agreement in writing other than email. Monitoring: AstraZeneca UK Limited may monitor email traffic data and content for the purposes of the prevention and detection of crime, ensuring the security of our computer systems and checking Compliance with our Code of Conduct and Policies. -Original Message- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of weliu Sent: 27 June 2012 02:07 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] The effect of His-tag location on crystallization Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu
Re: [ccp4bb] The effect of His-tag location on crystallization
Most of the comments you will get will be anecdotal in that people will report the successful results and do not take the time or effort to characterize the less successful results. This often occurs because the tagged portion of the protein is most often disordered, even in the best crystals. Thus, other than saying tagging on this end works, but tagging on that end doesn't, there is little more you can say. Each case will be different, and it is almost impossible to arrive at any generalized conclusion. We prefer C-terminal tagged proteins for a number of reasons, but if an N-terminally tagged protein crystallizes well, so be it. Of the dozens of N- and C-tagged protein structures we have solved in my lab and with collaborators, I have only seen one case of an ordered His-tag: the His residues had coordinated Cd ions, which proved essential for getting good crystals. However, beyond that there was not much more to say. For your protein and the resulting crystals, an N-terminally tagged protein crystallized well. Whether you can draw any more conclusions from these results depends on characterizing crystals of both N- and C-tagged proteins. Just assuming that the C-tagged protein is trying to crystallize in the same or related crystal form as the N-tagged protein is an unwarranted assumption without experimental evidence to back it up. That is why most groups just run with the winner. Cheers, Michael R. Michael Garavito, Ph.D. Professor of Biochemistry Molecular Biology 603 Wilson Rd., Rm. 513 Michigan State University East Lansing, MI 48824-1319 Office: (517) 355-9724 Lab: (517) 353-9125 FAX: (517) 353-9334Email: rmgarav...@gmail.com On Jun 26, 2012, at 9:06 PM, weliu wrote: Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu
Re: [ccp4bb] The effect of His-tag location on crystallization
With Flp recombinase - DNA complexes, a C-terminal His tag triggered a different (but sadly not better) crystal form, and the His side chains packed against the bases at the end of a neighboring DNA duplex. = Phoebe A. Rice Dept. of Biochemistry Molecular Biology The University of Chicago phone 773 834 1723 http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123 http://www.rsc.org/shop/books/2008/9780854042722.asp Original message Date: Wed, 27 Jun 2012 10:14:58 -0400 From: CCP4 bulletin board CCP4BB@JISCMAIL.AC.UK (on behalf of R. M. Garavito rmgarav...@gmail.com) Subject: Re: [ccp4bb] The effect of His-tag location on crystallization To: CCP4BB@JISCMAIL.AC.UK Most of the comments you will get will be anecdotal in that people will report the successful results and do not take the time or effort to characterize the less successful results. This often occurs because the tagged portion of the protein is most often disordered, even in the best crystals. Thus, other than saying tagging on this end works, but tagging on that end doesn't, there is little more you can say. Each case will be different, and it is almost impossible to arrive at any generalized conclusion. We prefer C-terminal tagged proteins for a number of reasons, but if an N-terminally tagged protein crystallizes well, so be it. Of the dozens of N- and C-tagged protein structures we have solved in my lab and with collaborators, I have only seen one case of an ordered His-tag: the His residues had coordinated Cd ions, which proved essential for getting good crystals. However, beyond that there was not much more to say. For your protein and the resulting crystals, an N-terminally tagged protein crystallized well. Whether you can draw any more conclusions from these results depends on characterizing crystals of both N- and C-tagged proteins. Just assuming that the C-tagged protein is trying to crystallize in the same or related crystal form as the N-tagged protein is an unwarranted assumption without experimental evidence to back it up. That is why most groups just run with the winner. Cheers, Michael R. Michael Garavito, Ph.D. Professor of Biochemistry Molecular Biology 603 Wilson Rd., Rm. 513 Michigan State University East Lansing, MI 48824-1319 Office: (517) 355-9724 Lab: (517) 353-9125 FAX: (517) 353-9334 Email: rmgarav...@gmail.com On Jun 26, 2012, at 9:06 PM, weliu wrote: Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu
Re: [ccp4bb] The effect of His-tag location on crystallization
I think it was an N-terminal RGS-type His tag in 3O8Y (human lipoxygenase) that mediated crystal contacts with a symmetry related molecule. As I recall, this tag composed a B-strand that formed a nice interface with a native B-strand of the symmetry related molecule. Pretty cool... -Brad On Wed, Jun 27, 2012 at 11:00 AM, Phoebe Rice pr...@uchicago.edu wrote: With Flp recombinase - DNA complexes, a C-terminal His tag triggered a different (but sadly not better) crystal form, and the His side chains packed against the bases at the end of a neighboring DNA duplex. = Phoebe A. Rice Dept. of Biochemistry Molecular Biology The University of Chicago phone 773 834 1723 http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123 http://www.rsc.org/shop/books/2008/9780854042722.asp Original message Date: Wed, 27 Jun 2012 10:14:58 -0400 From: CCP4 bulletin board CCP4BB@JISCMAIL.AC.UK (on behalf of R. M. Garavito rmgarav...@gmail.com) Subject: Re: [ccp4bb] The effect of His-tag location on crystallization To: CCP4BB@JISCMAIL.AC.UK Most of the comments you will get will be anecdotal in that people will report the successful results and do not take the time or effort to characterize the less successful results. This often occurs because the tagged portion of the protein is most often disordered, even in the best crystals. Thus, other than saying tagging on this end works, but tagging on that end doesn't, there is little more you can say. Each case will be different, and it is almost impossible to arrive at any generalized conclusion. We prefer C-terminal tagged proteins for a number of reasons, but if an N-terminally tagged protein crystallizes well, so be it. Of the dozens of N- and C-tagged protein structures we have solved in my lab and with collaborators, I have only seen one case of an ordered His-tag: the His residues had coordinated Cd ions, which proved essential for getting good crystals. However, beyond that there was not much more to say. For your protein and the resulting crystals, an N-terminally tagged protein crystallized well. Whether you can draw any more conclusions from these results depends on characterizing crystals of both N- and C-tagged proteins. Just assuming that the C-tagged protein is trying to crystallize in the same or related crystal form as the N-tagged protein is an unwarranted assumption without experimental evidence to back it up. That is why most groups just run with the winner. Cheers, Michael R. Michael Garavito, Ph.D. Professor of Biochemistry Molecular Biology 603 Wilson Rd., Rm. 513 Michigan State University East Lansing, MI 48824-1319 Office: (517) 355-9724 Lab: (517) 353-9125 FAX: (517) 353-9334 Email: rmgarav...@gmail.com On Jun 26, 2012, at 9:06 PM, weliu wrote: Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu
Re: [ccp4bb] The effect of His-tag location on crystallization
Here's another example: http://www.pdb.org/pdb/explore/explore.do?structureId=2F62 dimer with His-tag-ears without His6-tag this would not have been possible. Jürgen On Jun 27, 2012, at 12:04 PM, Brad Bennett wrote: I think it was an N-terminal RGS-type His tag in 3O8Y (human lipoxygenase) that mediated crystal contacts with a symmetry related molecule. As I recall, this tag composed a B-strand that formed a nice interface with a native B-strand of the symmetry related molecule. Pretty cool... -Brad On Wed, Jun 27, 2012 at 11:00 AM, Phoebe Rice pr...@uchicago.edumailto:pr...@uchicago.edu wrote: With Flp recombinase - DNA complexes, a C-terminal His tag triggered a different (but sadly not better) crystal form, and the His side chains packed against the bases at the end of a neighboring DNA duplex. = Phoebe A. Rice Dept. of Biochemistry Molecular Biology The University of Chicago phone 773 834 1723tel:773%20834%201723 http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123 http://www.rsc.org/shop/books/2008/9780854042722.asp Original message Date: Wed, 27 Jun 2012 10:14:58 -0400 From: CCP4 bulletin board CCP4BB@JISCMAIL.AC.UKmailto:CCP4BB@JISCMAIL.AC.UK (on behalf of R. M. Garavito rmgarav...@gmail.commailto:rmgarav...@gmail.com) Subject: Re: [ccp4bb] The effect of His-tag location on crystallization To: CCP4BB@JISCMAIL.AC.UKmailto:CCP4BB@JISCMAIL.AC.UK Most of the comments you will get will be anecdotal in that people will report the successful results and do not take the time or effort to characterize the less successful results. This often occurs because the tagged portion of the protein is most often disordered, even in the best crystals. Thus, other than saying tagging on this end works, but tagging on that end doesn't, there is little more you can say. Each case will be different, and it is almost impossible to arrive at any generalized conclusion. We prefer C-terminal tagged proteins for a number of reasons, but if an N-terminally tagged protein crystallizes well, so be it. Of the dozens of N- and C-tagged protein structures we have solved in my lab and with collaborators, I have only seen one case of an ordered His-tag: the His residues had coordinated Cd ions, which proved essential for getting good crystals. However, beyond that there was not much more to say. For your protein and the resulting crystals, an N-terminally tagged protein crystallized well. Whether you can draw any more conclusions from these results depends on characterizing crystals of both N- and C-tagged proteins. Just assuming that the C-tagged protein is trying to crystallize in the same or related crystal form as the N-tagged protein is an unwarranted assumption without experimental evidence to back it up. That is why most groups just run with the winner. Cheers, Michael R. Michael Garavito, Ph.D. Professor of Biochemistry Molecular Biology 603 Wilson Rd., Rm. 513 Michigan State University East Lansing, MI 48824-1319 Office: (517) 355-9724tel:%28517%29%20355-9724 Lab: (517) 353-9125tel:%28517%29%20353-9125 FAX: (517) 353-9334tel:%28517%29%20353-9334 Email: rmgarav...@gmail.commailto:rmgarav...@gmail.com On Jun 26, 2012, at 9:06 PM, weliu wrote: Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu .. Jürgen Bosch Johns Hopkins University Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Office: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-2926 http://web.mac.com/bosch_lab/
Re: [ccp4bb] The effect of His-tag location on crystallization
Or indeed support surreal structures :-))
(PMID: 11853672 vs PMID: 14749821 and so on)
--
A. Radu Aricescu, PhD
University Research Lecturer
MRC Career Development Award Fellow
University of Oxford
Wellcome Trust Centre for Human Genetics
Division of Structural Biology
Roosevelt Drive, Oxford OX3 7BN
United Kingdom
Phone: +44-1865-287564
Fax: +44-1865-287547
Original message
Date: Wed, 27 Jun 2012 12:21:22 -0400
From: CCP4 bulletin board CCP4BB@JISCMAIL.AC.UK (on behalf of Bosch,
Juergen jubo...@jhsph.edu)
Subject: Re: [ccp4bb] The effect of His-tag location on crystallization
To: CCP4BB@JISCMAIL.AC.UK
Here's another example:
http://www.pdb.org/pdb/explore/explore.do?structureId=2F62
dimer with His-tag-ears without His6-tag this
would not have been possible.
Jürgen
On Jun 27, 2012, at 12:04 PM, Brad Bennett wrote:
I think it was an N-terminal RGS-type His tag in
3O8Y (human lipoxygenase) that mediated crystal
contacts with a symmetry related molecule. As I
recall, this tag composed a B-strand that formed a
nice interface with a native B-strand of the
symmetry related molecule. Pretty cool...
-Brad
On Wed, Jun 27, 2012 at 11:00 AM, Phoebe Rice
pr...@uchicago.edu wrote:
With Flp recombinase - DNA complexes, a
C-terminal His tag triggered a different (but
sadly not better) crystal form, and the His side
chains packed against the bases at the end of a
neighboring DNA duplex.
=
Phoebe A. Rice
Dept. of Biochemistry Molecular Biology
The University of Chicago
phone 773 834 1723
http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123
http://www.rsc.org/shop/books/2008/9780854042722.asp
Original message
Date: Wed, 27 Jun 2012 10:14:58 -0400
From: CCP4 bulletin board
CCP4BB@JISCMAIL.AC.UK (on behalf of R. M.
Garavito rmgarav...@gmail.com)
Subject: Re: [ccp4bb] The effect of His-tag
location on crystallization
To: CCP4BB@JISCMAIL.AC.UK
Most of the comments you will get will be
anecdotal
in that people will report the successful
results
and do not take the time or effort to
characterize
the less successful results. This often
occurs
because the tagged portion of the protein is
most
often disordered, even in the best crystals.
Thus,
other than saying tagging on this end
works, but
tagging on that end doesn't, there is
little more
you can say. Each case will be different,
and it is
almost impossible to arrive at any
generalized
conclusion.
We prefer C-terminal tagged proteins for a
number of
reasons, but if an N-terminally tagged
protein
crystallizes well, so be it. Of the dozens
of N-
and C-tagged protein structures we have
solved in my
lab and with collaborators, I have only seen
one
case of an ordered His-tag: the His
residues had
coordinated Cd ions, which proved essential
for
getting good crystals. However, beyond that
there
was not much more to say.
For your protein and the resulting crystals,
an
N-terminally tagged protein crystallized
well.
Whether you can draw any more conclusions
from
these results depends on characterizing
crystals of
both N- and C-tagged proteins. Just
assuming that
the C-tagged protein is trying to
crystallize in the
same or related crystal form as the N-tagged
protein
is an unwarranted assumption without
experimental
evidence to back it up. That is why most
groups
just run with the winner.
Cheers,
Michael
R. Michael Garavito, Ph.D.
Professor of Biochemistry Molecular
Biology
603 Wilson Rd., Rm. 513
Michigan State University
East Lansing, MI 48824-1319
Office: (517) 355-9724 Lab: (517)
353-9125
FAX: (517) 353-9334
Email: rmgarav...@gmail.com
On Jun 26, 2012, at 9:06 PM, weliu wrote:
Dear all,
We crystallized a protein and found that
crystal
quality greatly depended on the location
of
His-tag. When a His-tag was added at the
C-terminus, only crystalline
Re: [ccp4bb] The effect of His-tag location on crystallization
Human leukotriene C4 synthase (PDB accession code: 2UUI) is another example, illustrating how an N-terminal polyhistidine-tag, in conjunction with metals, presumably facilitated crystallization. On Jun 27, 2012, at 12:04 PM, Brad Bennett wrote: I think it was an N-terminal RGS-type His tag in 3O8Y (human lipoxygenase) that mediated crystal contacts with a symmetry related molecule. As I recall, this tag composed a B-strand that formed a nice interface with a native B-strand of the symmetry related molecule. Pretty cool... -Brad On Wed, Jun 27, 2012 at 11:00 AM, Phoebe Rice pr...@uchicago.edu wrote: With Flp recombinase - DNA complexes, a C-terminal His tag triggered a different (but sadly not better) crystal form, and the His side chains packed against the bases at the end of a neighboring DNA duplex. = Phoebe A. Rice Dept. of Biochemistry Molecular Biology The University of Chicago phone 773 834 1723 http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123 http://www.rsc.org/shop/books/2008/9780854042722.asp Original message Date: Wed, 27 Jun 2012 10:14:58 -0400 From: CCP4 bulletin board CCP4BB@JISCMAIL.AC.UK (on behalf of R. M. Garavito rmgarav...@gmail.com) Subject: Re: [ccp4bb] The effect of His-tag location on crystallization To: CCP4BB@JISCMAIL.AC.UK Most of the comments you will get will be anecdotal in that people will report the successful results and do not take the time or effort to characterize the less successful results. This often occurs because the tagged portion of the protein is most often disordered, even in the best crystals. Thus, other than saying tagging on this end works, but tagging on that end doesn't, there is little more you can say. Each case will be different, and it is almost impossible to arrive at any generalized conclusion. We prefer C-terminal tagged proteins for a number of reasons, but if an N-terminally tagged protein crystallizes well, so be it. Of the dozens of N- and C-tagged protein structures we have solved in my lab and with collaborators, I have only seen one case of an ordered His-tag: the His residues had coordinated Cd ions, which proved essential for getting good crystals. However, beyond that there was not much more to say. For your protein and the resulting crystals, an N-terminally tagged protein crystallized well. Whether you can draw any more conclusions from these results depends on characterizing crystals of both N- and C-tagged proteins. Just assuming that the C-tagged protein is trying to crystallize in the same or related crystal form as the N-tagged protein is an unwarranted assumption without experimental evidence to back it up. That is why most groups just run with the winner. Cheers, Michael R. Michael Garavito, Ph.D. Professor of Biochemistry Molecular Biology 603 Wilson Rd., Rm. 513 Michigan State University East Lansing, MI 48824-1319 Office: (517) 355-9724 Lab: (517) 353-9125 FAX: (517) 353-9334 Email: rmgarav...@gmail.com On Jun 26, 2012, at 9:06 PM, weliu wrote: Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu
Re: [ccp4bb] The effect of His-tag location on crystallization
You may want to have a look at 3ur7 and 3ur8. I have also another example of a glycohydrolytic enzyme with an N-terminal His-tag sitting in the active site of a symmetry-related molecule (not deposited yet). Karolina On 27/6/2012, Brad Bennett bradbennet...@gmail.com wrote: I think it was an N-terminal RGS-type His tag in 3O8Y (human lipoxygenase) that mediated crystal contacts with a symmetry related molecule. As I recall, this tag composed a B-strand that formed a nice interface with a native B-strand of the symmetry related molecule. Pretty cool... -Brad On Wed, Jun 27, 2012 at 11:00 AM, Phoebe Rice pr...@uchicago.edu wrote: With Flp recombinase - DNA complexes, a C-terminal His tag triggered a different (but sadly not better) crystal form, and the His side chains packed against the bases at the end of a neighboring DNA duplex. = Phoebe A. Rice Dept. of Biochemistry Molecular Biology The University of Chicago phone 773 834 1723 http://bmb.bsd.uchicago.edu/Faculty_and_Research/01_Faculty/01_Faculty_Alphabetically.php?faculty_id=123 http://www.rsc.org/shop/books/2008/9780854042722.asp Original message Date: Wed, 27 Jun 2012 10:14:58 -0400 From: CCP4 bulletin board CCP4BB@JISCMAIL.AC.UK (on behalf of R. M. Garavito rmgarav...@gmail.com) Subject: Re: [ccp4bb] The effect of His-tag location on crystallization To: CCP4BB@JISCMAIL.AC.UK Most of the comments you will get will be anecdotal in that people will report the successful results and do not take the time or effort to characterize the less successful results. This often occurs because the tagged portion of the protein is most often disordered, even in the best crystals. Thus, other than saying tagging on this end works, but tagging on that end doesn't, there is little more you can say. Each case will be different, and it is almost impossible to arrive at any generalized conclusion. We prefer C-terminal tagged proteins for a number of reasons, but if an N-terminally tagged protein crystallizes well, so be it. Of the dozens of N- and C-tagged protein structures we have solved in my lab and with collaborators, I have only seen one case of an ordered His-tag: the His residues had coordinated Cd ions, which proved essential for getting good crystals. However, beyond that there was not much more to say. For your protein and the resulting crystals, an N-terminally tagged protein crystallized well. Whether you can draw any more conclusions from these results depends on characterizing crystals of both N- and C-tagged proteins. Just assuming that the C-tagged protein is trying to crystallize in the same or related crystal form as the N-tagged protein is an unwarranted assumption without experimental evidence to back it up. That is why most groups just run with the winner. Cheers, Michael R. Michael Garavito, Ph.D. Professor of Biochemistry Molecular Biology 603 Wilson Rd., Rm. 513 Michigan State University East Lansing, MI 48824-1319 Office: (517) 355-9724 Lab: (517) 353-9125 FAX: (517) 353-9334 Email: rmgarav...@gmail.com On Jun 26, 2012, at 9:06 PM, weliu wrote: Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu
Re: [ccp4bb] The effect of His-tag location on crystallization
Google yields amongst others: His-tag impact on structure Acta Cryst. (2007). D63, 295301 ...quäl dich. -Original Message- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of weliu Sent: Tuesday, June 26, 2012 6:07 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] The effect of His-tag location on crystallization Dear all, We crystallized a protein and found that crystal quality greatly depended on the location of His-tag. When a His-tag was added at the C-terminus, only crystalline precipitate or spherical quasi crystals were grown. However, when the His-tag was moved to the N-terminus, single crystals were grown under a number of conditions, and the best one diffracted to 1.7 angstrom after optimization. I was wondering if there were published reports describing similar cases. Thank you in advance Wei Liu
