1tmo
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The periplasmic trimethylamine N-oxide (TMAO) reductase from the marine | + | The periplasmic trimethylamine N-oxide (TMAO) reductase from the marine bacteria Shewanella massilia is involved in a respiratory chain, having trimethylamine N-oxide as terminal electron acceptor. This molybdoenzyme belongs to the dimethyl sulfoxide (DMSO) reductase family, but has a different substrate specificity than its homologous enzyme. While the DMSO reductases reduce a broad spectra of organic S-oxide and N-oxide compounds, TMAO reductase from Shewanella massilia reduces only TMAO as the natural compound. The crystal structure was solved by molecular replacement with the coordinates of the DMSO reductase from Rhodobacter sphaeroides. The overall fold of the protein structure is essentially the same as the DMSO reductase structures, organized into four domains. The molybdenum coordination sphere is closest to that described in the DMSO reductase of Rhodobacter capsulatus. The structural differences found in the protein environment of the active site could be related to the differences in substrate specificity of these enzymes. In close vicinity of the molybdenum ion a tyrosine residue is missing in the TMAO reductase, leaving a greater space accessible to the solvent. This tyrosine residue has contacts to the oxo groups in the DMSO reductase structures. The arrangement and number of charged residues lining the inner surface of the funnel-like entrance to the active site, is different in the TMAO reductase than in the DMSO reductases from Rhodobacter species. Furthermore a surface loop at the top of the active-site funnel, for which no density was present in the DMSO reductase structures, is well defined in the oxidized form of the TMAO reductase structure, and is located on the border of the funnel-like entrance of the active center. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Giordano, G.]] | [[Category: Giordano, G.]] | ||
[[Category: Mejean, V.]] | [[Category: Mejean, V.]] | ||
| - | [[Category: Santos, J | + | [[Category: Santos, J P.Dos.]] |
[[Category: 2MD]] | [[Category: 2MD]] | ||
[[Category: 2MO]] | [[Category: 2MO]] | ||
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[[Category: tmao reductase]] | [[Category: tmao reductase]] | ||
| - | ''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 15:15:14 2008'' |
Revision as of 13:15, 21 February 2008
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TRIMETHYLAMINE N-OXIDE REDUCTASE FROM SHEWANELLA MASSILIA
Overview
The periplasmic trimethylamine N-oxide (TMAO) reductase from the marine bacteria Shewanella massilia is involved in a respiratory chain, having trimethylamine N-oxide as terminal electron acceptor. This molybdoenzyme belongs to the dimethyl sulfoxide (DMSO) reductase family, but has a different substrate specificity than its homologous enzyme. While the DMSO reductases reduce a broad spectra of organic S-oxide and N-oxide compounds, TMAO reductase from Shewanella massilia reduces only TMAO as the natural compound. The crystal structure was solved by molecular replacement with the coordinates of the DMSO reductase from Rhodobacter sphaeroides. The overall fold of the protein structure is essentially the same as the DMSO reductase structures, organized into four domains. The molybdenum coordination sphere is closest to that described in the DMSO reductase of Rhodobacter capsulatus. The structural differences found in the protein environment of the active site could be related to the differences in substrate specificity of these enzymes. In close vicinity of the molybdenum ion a tyrosine residue is missing in the TMAO reductase, leaving a greater space accessible to the solvent. This tyrosine residue has contacts to the oxo groups in the DMSO reductase structures. The arrangement and number of charged residues lining the inner surface of the funnel-like entrance to the active site, is different in the TMAO reductase than in the DMSO reductases from Rhodobacter species. Furthermore a surface loop at the top of the active-site funnel, for which no density was present in the DMSO reductase structures, is well defined in the oxidized form of the TMAO reductase structure, and is located on the border of the funnel-like entrance of the active center.
About this Structure
1TMO is a Single protein structure of sequence from Shewanella massilia with and as ligands. Active as Trimethylamine-N-oxide reductase, with EC number 1.6.6.9 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Crystal structure of oxidized trimethylamine N-oxide reductase from Shewanella massilia at 2.5 A resolution., Czjzek M, Dos Santos JP, Pommier J, Giordano G, Mejean V, Haser R, J Mol Biol. 1998 Nov 27;284(2):435-47. PMID:9813128
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