1bbh
From Proteopedia
(New page: 200px<br /><applet load="1bbh" size="450" color="white" frame="true" align="right" spinBox="true" caption="1bbh, resolution 1.8Å" /> '''ATOMIC STRUCTURE OF A...) |
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| - | [[Image:1bbh.gif|left|200px]]<br /><applet load="1bbh" size=" | + | [[Image:1bbh.gif|left|200px]]<br /><applet load="1bbh" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1bbh, resolution 1.8Å" /> | caption="1bbh, resolution 1.8Å" /> | ||
'''ATOMIC STRUCTURE OF A CYTOCHROME C' WITH AN UNUSUAL LIGAND-CONTROLLED DIMER DISSOCIATION AT 1.8 ANGSTROMS RESOLUTION'''<br /> | '''ATOMIC STRUCTURE OF A CYTOCHROME C' WITH AN UNUSUAL LIGAND-CONTROLLED DIMER DISSOCIATION AT 1.8 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystallographic structure of cytochrome c' from the purple | + | The crystallographic structure of cytochrome c' from the purple phototrophic bacterium Chromatium vinosum (CVCP) has been determined at 1.8 A resolution using multiple isomorphous replacement. The molecule is a dimer, with each 131-residue chain folding as a four-helical bundle incorporating a covalently bound heme group at the core. This structure is the third of the ubiquitous cytochromes c' to be solved and is similar to the known structures of cytochrome c' from R. molischianum (RMCP) and R. rubrum (RRCP). CVCP is unique in exhibiting ligand-controlled dimer dissociation while RMCP and RRCP do not. The Tyr16 side-chain, which replaced Met16 in RMCP and Leu14 in RRCP, is parallel to the heme plane and located directly above the sixth ligand site of the heme Fe. Any ligand binding to this site, such as CO or CN-, must move the Tyr16 side-chain, which would be expected to cause other conformational changes of helix A, which contributes to the dimer interface, and consequently disrupting the dimer. Thus, the crystallographic structure of CVCP suggests a mechanism for dimer dissociation upon ligand binding. The dimer interface specificity is due to a lock and key shape complementarity of hydrophobic residues and not to any charge complementarity or cross-interface hydrogen bonds as is common in other protein-protein interfaces. The co-ordinates have been deposited in the Brookhaven Data Bank (entry P1BBH). |
==About this Structure== | ==About this Structure== | ||
| - | 1BBH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Allochromatium_vinosum Allochromatium vinosum] with HEM as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1BBH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Allochromatium_vinosum Allochromatium vinosum] with <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BBH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Allochromatium vinosum]] | [[Category: Allochromatium vinosum]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Mcree, D | + | [[Category: Mcree, D E.]] |
[[Category: Ren, Z.]] | [[Category: Ren, Z.]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
[[Category: electron transport(heme protein)]] | [[Category: electron transport(heme protein)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:53:33 2008'' |
Revision as of 09:53, 21 February 2008
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ATOMIC STRUCTURE OF A CYTOCHROME C' WITH AN UNUSUAL LIGAND-CONTROLLED DIMER DISSOCIATION AT 1.8 ANGSTROMS RESOLUTION
Overview
The crystallographic structure of cytochrome c' from the purple phototrophic bacterium Chromatium vinosum (CVCP) has been determined at 1.8 A resolution using multiple isomorphous replacement. The molecule is a dimer, with each 131-residue chain folding as a four-helical bundle incorporating a covalently bound heme group at the core. This structure is the third of the ubiquitous cytochromes c' to be solved and is similar to the known structures of cytochrome c' from R. molischianum (RMCP) and R. rubrum (RRCP). CVCP is unique in exhibiting ligand-controlled dimer dissociation while RMCP and RRCP do not. The Tyr16 side-chain, which replaced Met16 in RMCP and Leu14 in RRCP, is parallel to the heme plane and located directly above the sixth ligand site of the heme Fe. Any ligand binding to this site, such as CO or CN-, must move the Tyr16 side-chain, which would be expected to cause other conformational changes of helix A, which contributes to the dimer interface, and consequently disrupting the dimer. Thus, the crystallographic structure of CVCP suggests a mechanism for dimer dissociation upon ligand binding. The dimer interface specificity is due to a lock and key shape complementarity of hydrophobic residues and not to any charge complementarity or cross-interface hydrogen bonds as is common in other protein-protein interfaces. The co-ordinates have been deposited in the Brookhaven Data Bank (entry P1BBH).
About this Structure
1BBH is a Single protein structure of sequence from Allochromatium vinosum with as ligand. Full crystallographic information is available from OCA.
Reference
Atomic structure of a cytochrome c' with an unusual ligand-controlled dimer dissociation at 1.8 A resolution., Ren Z, Meyer T, McRee DE, J Mol Biol. 1993 Nov 20;234(2):433-45. PMID:8230224
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