1ddi
From Proteopedia
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|PDB= 1ddi |SIZE=350|CAPTION= <scene name='initialview01'>1ddi</scene>, resolution 2.51Å | |PDB= 1ddi |SIZE=350|CAPTION= <scene name='initialview01'>1ddi</scene>, resolution 2.51Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene> | + | |LIGAND= <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=NAP:NADP+NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NAP</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Sulfite_reductase_(NADPH) Sulfite reductase (NADPH)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.1.2 1.8.1.2] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Sulfite_reductase_(NADPH) Sulfite reductase (NADPH)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.1.2 1.8.1.2] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1ddg|1DDG]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ddi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ddi OCA], [http://www.ebi.ac.uk/pdbsum/1ddi PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1ddi RCSB]</span> | ||
}} | }} | ||
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[[Category: Pignol, D.]] | [[Category: Pignol, D.]] | ||
[[Category: Zeghouf, M.]] | [[Category: Zeghouf, M.]] | ||
| - | [[Category: FAD]] | ||
| - | [[Category: NAP]] | ||
[[Category: cytochrome p450 reductase]] | [[Category: cytochrome p450 reductase]] | ||
[[Category: flavoprotein]] | [[Category: flavoprotein]] | ||
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[[Category: modular protein]] | [[Category: modular protein]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:39:25 2008'' |
Revision as of 16:39, 30 March 2008
| |||||||
| , resolution 2.51Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Activity: | Sulfite reductase (NADPH), with EC number 1.8.1.2 | ||||||
| Related: | 1DDG
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF SIR-FP60
Overview
Escherichia coli NADPH-sulfite reductase (SiR) is a 780 kDa multimeric hemoflavoprotein composed of eight alpha-subunits (SiR-FP) and four beta-subunits (SiR-HP) that catalyses the six electron reduction of sulfite to sulfide. Each beta-subunit contains a Fe4S4 cluster and a siroheme, and each alpha-subunit binds one FAD and one FMN as prosthetic groups. The FAD gets electrons from NADPH, and the FMN transfers the electrons to the metal centers of the beta-subunit for sulfite reduction. We report here the 1.94 A X-ray structure of SiR-FP60, a recombinant monomeric fragment of SiR-FP that binds both FAD and FMN and retains the catalytic properties of the native protein. The structure can be divided into three domains. The carboxy-terminal part of the enzyme is composed of an antiparallel beta-barrel which binds the FAD, and a variant of the classical pyridine dinucleotide binding fold which binds NADPH. These two domains form the canonic FNR-like module, typical of the ferredoxin NADP+ reductase family. By analogy with the structure of the cytochrome P450 reductase, the third domain, composed of seven alpha-helices, is supposed to connect the FNR-like module to the N-terminal flavodoxine-like module. In four different crystal forms, the FMN-binding module is absent from electron density maps, although mass spectroscopy, amino acid sequencing and activity experiments carried out on dissolved crystals indicate that a functional module is present in the protein. Our results clearly indicate that the interaction between the FNR-like and the FMN-like modules displays lower affinity than in the case of cytochrome P450 reductase. The flexibility of the FMN-binding domain may be related, as observed in the case of cytochrome bc1, to a domain reorganisation in the course of electron transfer. Thus, a movement of the FMN-binding domain relative to the rest of the enzyme may be a requirement for its optimal positioning relative to both the FNR-like module and the beta-subunit.
About this Structure
1DDI is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Four crystal structures of the 60 kDa flavoprotein monomer of the sulfite reductase indicate a disordered flavodoxin-like module., Gruez A, Pignol D, Zeghouf M, Coves J, Fontecave M, Ferrer JL, Fontecilla-Camps JC, J Mol Biol. 2000 May 26;299(1):199-212. PMID:10860732
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