2c8s
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The structure of cytochrome cL from Methylobacterium extorquens has been | + | The structure of cytochrome cL from Methylobacterium extorquens has been determined by X-ray crystallography to a resolution of 1.6 A. This unusually large, acidic cytochrome is the physiological electron acceptor for the quinoprotein methanol dehydrogenase in the periplasm of methylotrophic bacteria. Its amino acid sequence is completely different from that of other cytochromes but its X-ray structure reveals a core that is typical of class I cytochromes c, having alpha-helices folded into a compact structure enclosing the single haem c prosthetic group and leaving one edge of the haem exposed. The haem is bound through thioether bonds to Cys65 and Cys68, and the fifth ligand to the haem iron is provided by His69. Remarkably, the sixth ligand is provided by His112, and not by Met109, which had been shown to be the sixth ligand in solution. Cytochrome cL is unusual in having a disulphide bridge that tethers the long C-terminal extension to the body of the structure. The crystal structure reveals that, close to the inner haem propionate, there is tightly bound calcium ion that is likely to be involved in stabilization of the redox potential, and that may be important in the flow of electrons from reduced pyrroloquinoline quinone in methanol dehydrogenase to the haem of cytochrome cL. As predicted, both haem propionates are exposed to solvent, accounting for the unusual influence of pH on the redox potential of this cytochrome. |
==About this Structure== | ==About this Structure== | ||
| - | 2C8S is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methylobacterium_extorquens Methylobacterium extorquens] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure | + | 2C8S is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methylobacterium_extorquens Methylobacterium extorquens] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure supersedes the now removed PDB entry 1UMM. Known structural/functional Site: <scene name='pdbsite=AC1:Ca+Binding+Site+For+Chain+A'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2C8S OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Anthony, C.]] | [[Category: Anthony, C.]] | ||
[[Category: Coates, L.]] | [[Category: Coates, L.]] | ||
| - | [[Category: Cooper, J | + | [[Category: Cooper, J B.]] |
[[Category: Erskine, P.]] | [[Category: Erskine, P.]] | ||
[[Category: Gill, R.]] | [[Category: Gill, R.]] | ||
[[Category: Mohammed, F.]] | [[Category: Mohammed, F.]] | ||
| - | [[Category: Williams, P | + | [[Category: Williams, P A.]] |
| - | [[Category: Wood, S | + | [[Category: Wood, S P.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
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[[Category: metal-binding]] | [[Category: metal-binding]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:46:09 2008'' |
Revision as of 14:46, 21 February 2008
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CYTOCHROME CL FROM METHYLOBACTERIUM EXTORQUENS
Overview
The structure of cytochrome cL from Methylobacterium extorquens has been determined by X-ray crystallography to a resolution of 1.6 A. This unusually large, acidic cytochrome is the physiological electron acceptor for the quinoprotein methanol dehydrogenase in the periplasm of methylotrophic bacteria. Its amino acid sequence is completely different from that of other cytochromes but its X-ray structure reveals a core that is typical of class I cytochromes c, having alpha-helices folded into a compact structure enclosing the single haem c prosthetic group and leaving one edge of the haem exposed. The haem is bound through thioether bonds to Cys65 and Cys68, and the fifth ligand to the haem iron is provided by His69. Remarkably, the sixth ligand is provided by His112, and not by Met109, which had been shown to be the sixth ligand in solution. Cytochrome cL is unusual in having a disulphide bridge that tethers the long C-terminal extension to the body of the structure. The crystal structure reveals that, close to the inner haem propionate, there is tightly bound calcium ion that is likely to be involved in stabilization of the redox potential, and that may be important in the flow of electrons from reduced pyrroloquinoline quinone in methanol dehydrogenase to the haem of cytochrome cL. As predicted, both haem propionates are exposed to solvent, accounting for the unusual influence of pH on the redox potential of this cytochrome.
About this Structure
2C8S is a Single protein structure of sequence from Methylobacterium extorquens with and as ligands. This structure supersedes the now removed PDB entry 1UMM. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The 1.6A X-ray structure of the unusual c-type cytochrome, cytochrome cL, from the methylotrophic bacterium Methylobacterium extorquens., Williams P, Coates L, Mohammed F, Gill R, Erskine P, Bourgeois D, Wood SP, Anthony C, Cooper JB, J Mol Biol. 2006 Mar 17;357(1):151-62. Epub 2006 Jan 5. PMID:16414073
Page seeded by OCA on Thu Feb 21 16:46:09 2008
Categories: Methylobacterium extorquens | Single protein | Anthony, C. | Coates, L. | Cooper, J B. | Erskine, P. | Gill, R. | Mohammed, F. | Williams, P A. | Wood, S P. | CA | HEM | Cytochrome c | Electron transport | Haem | Heme | Metal-binding
