1bkj
From Proteopedia
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==Overview== | ==Overview== | ||
| - | We report the structure of an NADPH:FMN oxidoreductase (flavin reductase | + | We report the structure of an NADPH:FMN oxidoreductase (flavin reductase P) that is involved in bioluminescence by providing reduced FMN to luciferase. The 1.8 A crystal structure of flavin reductase P from Vibrio harveyi was solved by multiple isomorphous replacement and reveals that the enzyme is a unique dimer of interlocking subunits, with 9352 A2 of surface area buried in the dimer interface. Each subunit comprises two domains. The first domain consists of a four-stranded antiparallel beta-sheet flanked by helices on either side. The second domain reaches out from one subunit and embraces the other subunit and is responsible for interlocking the two subunits. Our structure explains why flavin reductase P is specific for FMN as cofactor. FMN is recognized and tightly bound by a network of 16 hydrogen bonds, while steric considerations prevent the binding of FAD. A flexible loop containing a Lys and an Arg could account for the NADPH specificity. The structure reveals information about several aspects of the catalytic mechanism. For example, we show that the first step in catalysis, which is hydride transfer from C4 of NADPH to cofactor FMN, involves addition to the re face of the FMN, probably at the N5 position. The limited accessibility of the FMN binding pocket and the extensive FMN-protein hydrogen bond network are consistent with the observed ping-pong bisubstrate--biproduct reaction kinetics. Finally, we propose a model for how flavin reductase P might shuttle electrons between NADPH and luciferase. |
==About this Structure== | ==About this Structure== | ||
| - | 1BKJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_harveyi Vibrio harveyi] with <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=FMN:'>FMN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure | + | 1BKJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_harveyi Vibrio harveyi] with <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=FMN:'>FMN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure supersedes the now removed PDB entry 1CUM. Active as [http://en.wikipedia.org/wiki/Transferred_entry:_1.5.1.29 Transferred entry: 1.5.1.29], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.6.8.1 1.6.8.1] Known structural/functional Sites: <scene name='pdbsite=ASA:Fmn+Cofactor+Binding+Site-Chain+A'>ASA</scene> and <scene name='pdbsite=ASB:Fmn+Cofactor+Binding+Site-Chain+B'>ASB</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BKJ OCA]. |
==Reference== | ==Reference== | ||
Flavin reductase P: structure of a dimeric enzyme that reduces flavin., Tanner JJ, Lei B, Tu SC, Krause KL, Biochemistry. 1996 Oct 22;35(42):13531-9. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8885832 8885832] | Flavin reductase P: structure of a dimeric enzyme that reduces flavin., Tanner JJ, Lei B, Tu SC, Krause KL, Biochemistry. 1996 Oct 22;35(42):13531-9. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8885832 8885832] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Transferred entry: 1 | + | [[Category: Transferred entry: 1 5.1 29]] |
[[Category: Vibrio harveyi]] | [[Category: Vibrio harveyi]] | ||
| - | [[Category: Krause, K | + | [[Category: Krause, K L.]] |
[[Category: Lei, B.]] | [[Category: Lei, B.]] | ||
| - | [[Category: TU, S | + | [[Category: TU, S C.]] |
| - | [[Category: Tanner, J | + | [[Category: Tanner, J J.]] |
[[Category: FMN]] | [[Category: FMN]] | ||
[[Category: PO4]] | [[Category: PO4]] | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''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 11:56:17 2008'' |
Revision as of 09:56, 21 February 2008
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NADPH:FMN OXIDOREDUCTASE FROM VIBRIO HARVEYI
Overview
We report the structure of an NADPH:FMN oxidoreductase (flavin reductase P) that is involved in bioluminescence by providing reduced FMN to luciferase. The 1.8 A crystal structure of flavin reductase P from Vibrio harveyi was solved by multiple isomorphous replacement and reveals that the enzyme is a unique dimer of interlocking subunits, with 9352 A2 of surface area buried in the dimer interface. Each subunit comprises two domains. The first domain consists of a four-stranded antiparallel beta-sheet flanked by helices on either side. The second domain reaches out from one subunit and embraces the other subunit and is responsible for interlocking the two subunits. Our structure explains why flavin reductase P is specific for FMN as cofactor. FMN is recognized and tightly bound by a network of 16 hydrogen bonds, while steric considerations prevent the binding of FAD. A flexible loop containing a Lys and an Arg could account for the NADPH specificity. The structure reveals information about several aspects of the catalytic mechanism. For example, we show that the first step in catalysis, which is hydride transfer from C4 of NADPH to cofactor FMN, involves addition to the re face of the FMN, probably at the N5 position. The limited accessibility of the FMN binding pocket and the extensive FMN-protein hydrogen bond network are consistent with the observed ping-pong bisubstrate--biproduct reaction kinetics. Finally, we propose a model for how flavin reductase P might shuttle electrons between NADPH and luciferase.
About this Structure
1BKJ is a Single protein structure of sequence from Vibrio harveyi with and as ligands. This structure supersedes the now removed PDB entry 1CUM. Active as Transferred entry: 1.5.1.29, with EC number 1.6.8.1 Known structural/functional Sites: and . Full crystallographic information is available from OCA.
Reference
Flavin reductase P: structure of a dimeric enzyme that reduces flavin., Tanner JJ, Lei B, Tu SC, Krause KL, Biochemistry. 1996 Oct 22;35(42):13531-9. PMID:8885832
Page seeded by OCA on Thu Feb 21 11:56:17 2008
Categories: Single protein | Transferred entry: 1 5.1 29 | Vibrio harveyi | Krause, K L. | Lei, B. | TU, S C. | Tanner, J J. | FMN | PO4 | Flavoprotein | Luminescence | Nadp | Oxidoreductase
