1xvw: Difference between revisions

From Proteopedia
Jump to navigationJump to search
Newer edit →
OCA (talk | contribs)
Bots, Bureaucrats, journal, Administrators
3,331,613 edits
New page: left|200px<br /><applet load="1xvw" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xvw, resolution 1.9Å" /> '''Crystal Structure of ...
 
OCA (talk | contribs)
Bots, Bureaucrats, journal, Administrators
3,331,613 edits
No edit summary
Line 1: Line 1:
[[Image:1xvw.gif|left|200px]]<br /><applet load="1xvw" size="450" color="white" frame="true" align="right" spinBox="true"  
[[Image:1xvw.gif|left|200px]]<br /><applet load="1xvw" size="350" color="white" frame="true" align="right" spinBox="true"  
caption="1xvw, resolution 1.9&Aring;" />
caption="1xvw, resolution 1.9&Aring;" />
'''Crystal Structure of AhpE from Mycobacterium tuberculosis, a 1-Cys peroxiredoxin'''<br />
'''Crystal Structure of AhpE from Mycobacterium tuberculosis, a 1-Cys peroxiredoxin'''<br />


==Overview==
==Overview==
All living systems require protection against the damaging effects of, reactive oxygen species. The genome of Mycobacterium tuberculosis, the, cause of TB, encodes a number of peroxidases that are thought to be active, against organic and inorganic peroxides, and are likely to play a key role, in the ability of this organism to survive within the phagosomes of, macrophages. The open reading frame Rv2238c in M.tuberculosis encodes a, 153-residue protein AhpE, which is a peroxidase of the 1-Cys peroxiredoxin, (Prx) family. The crystal structure of AhpE, determined at 1.87 A, resolution (R(cryst)=0.179, R(free)=0.210), reveals a compact, single-domain protein with a thioredoxin fold. AhpE forms both dimers and, octamers; a tightly-associated dimer and a ring-like octamer, generated by, crystallographic 4-fold symmetry. In this native structure, the active, site Cys45 is in its oxidized, sulfenic acid (S-O-H) state. A second, crystal form of AhpE, obtained after soaking in sodium bromide and refined, at 1.90 A resolution (R(cryst)=0.242, R(free)=0.286), reveals the reduced, structure. In this structure, a conformational change in an external loop, in two of the four molecules in the asymmetric unit, allows Arg116 to, stabilise the Cys45 thiolate ion, and concomitantly closes a surface, channel. This channel is identified as the likely binding site for a, physiological reductant, and the conformational change is inferred to be, important for the reaction cycle of AhpE.
All living systems require protection against the damaging effects of reactive oxygen species. The genome of Mycobacterium tuberculosis, the cause of TB, encodes a number of peroxidases that are thought to be active against organic and inorganic peroxides, and are likely to play a key role in the ability of this organism to survive within the phagosomes of macrophages. The open reading frame Rv2238c in M.tuberculosis encodes a 153-residue protein AhpE, which is a peroxidase of the 1-Cys peroxiredoxin (Prx) family. The crystal structure of AhpE, determined at 1.87 A resolution (R(cryst)=0.179, R(free)=0.210), reveals a compact single-domain protein with a thioredoxin fold. AhpE forms both dimers and octamers; a tightly-associated dimer and a ring-like octamer, generated by crystallographic 4-fold symmetry. In this native structure, the active site Cys45 is in its oxidized, sulfenic acid (S-O-H) state. A second crystal form of AhpE, obtained after soaking in sodium bromide and refined at 1.90 A resolution (R(cryst)=0.242, R(free)=0.286), reveals the reduced structure. In this structure, a conformational change in an external loop, in two of the four molecules in the asymmetric unit, allows Arg116 to stabilise the Cys45 thiolate ion, and concomitantly closes a surface channel. This channel is identified as the likely binding site for a physiological reductant, and the conformational change is inferred to be important for the reaction cycle of AhpE.


==About this Structure==
==About this Structure==
1XVW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1XVW OCA].  
1XVW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XVW OCA].  


==Reference==
==Reference==
Line 13: Line 13:
[[Category: Mycobacterium tuberculosis]]
[[Category: Mycobacterium tuberculosis]]
[[Category: Single protein]]
[[Category: Single protein]]
[[Category: Baker, E.N.]]
[[Category: Baker, E N.]]
[[Category: Hung, L.W.]]
[[Category: Hung, L W.]]
[[Category: Kim, C.Y.]]
[[Category: Kim, C Y.]]
[[Category: Kim, M.Y.]]
[[Category: Kim, M Y.]]
[[Category: Lekin, T.]]
[[Category: Lekin, T.]]
[[Category: Li, S.]]
[[Category: Li, S.]]
[[Category: Lott, J.S.]]
[[Category: Lott, J S.]]
[[Category: Peterson, N.A.]]
[[Category: Peterson, N A.]]
[[Category: Segelke, B.W.]]
[[Category: Segelke, B W.]]
[[Category: TBSGC, TB.Structural.Genomics.Consortium.]]
[[Category: TBSGC, TB Structural Genomics Consortium.]]
[[Category: Yu, M.]]
[[Category: Yu, M.]]
[[Category: oxidized cystein sulfenic acid]]
[[Category: oxidized cystein sulfenic acid]]
Line 32: Line 32:
[[Category: thioredoxin fold]]
[[Category: thioredoxin fold]]


''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 06:22:59 2007''
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:59:10 2008''

Revision as of 13:59, 21 February 2008

File:1xvw.gif


1xvw, resolution 1.9Å

Drag the structure with the mouse to rotate

Crystal Structure of AhpE from Mycobacterium tuberculosis, a 1-Cys peroxiredoxin

Overview

All living systems require protection against the damaging effects of reactive oxygen species. The genome of Mycobacterium tuberculosis, the cause of TB, encodes a number of peroxidases that are thought to be active against organic and inorganic peroxides, and are likely to play a key role in the ability of this organism to survive within the phagosomes of macrophages. The open reading frame Rv2238c in M.tuberculosis encodes a 153-residue protein AhpE, which is a peroxidase of the 1-Cys peroxiredoxin (Prx) family. The crystal structure of AhpE, determined at 1.87 A resolution (R(cryst)=0.179, R(free)=0.210), reveals a compact single-domain protein with a thioredoxin fold. AhpE forms both dimers and octamers; a tightly-associated dimer and a ring-like octamer, generated by crystallographic 4-fold symmetry. In this native structure, the active site Cys45 is in its oxidized, sulfenic acid (S-O-H) state. A second crystal form of AhpE, obtained after soaking in sodium bromide and refined at 1.90 A resolution (R(cryst)=0.242, R(free)=0.286), reveals the reduced structure. In this structure, a conformational change in an external loop, in two of the four molecules in the asymmetric unit, allows Arg116 to stabilise the Cys45 thiolate ion, and concomitantly closes a surface channel. This channel is identified as the likely binding site for a physiological reductant, and the conformational change is inferred to be important for the reaction cycle of AhpE.

About this Structure

1XVW is a Single protein structure of sequence from Mycobacterium tuberculosis. Full crystallographic information is available from OCA.

Reference

Crystal Structure of AhpE from Mycobacterium tuberculosis, a 1-Cys peroxiredoxin., Li S, Peterson NA, Kim MY, Kim CY, Hung LW, Yu M, Lekin T, Segelke BW, Lott JS, Baker EN, J Mol Biol. 2005 Mar 4;346(4):1035-46. Epub 2005 Jan 25. PMID:15701515

Page seeded by OCA on Thu Feb 21 15:59:10 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "https://proteopedia.org/index.php?title=1xvw&oldid=169621"