1ddi

<table><tr><td colspan='2'>[[1ddi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DDI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1DDI FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=NAP:NADP+NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NAP</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1ddg|1ddg]]</div></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Sulfite_reductase_(NADPH) Sulfite reductase (NADPH)], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.1.2 1.8.1.2] </span></td></tr>

[[https://www.uniprot.org/uniprot/CYSJ_ECOLI CYSJ_ECOLI]] Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component.[HAMAP-Rule:MF_01541]

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== Publication Abstract from PubMed ==

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.

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<ref>PMID:10860732</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Bacillus coli migula 1895]]

[[Category: Coves, J]]

[[Category: Ferrer, J L]]

[[Category: Fontecave, M]]

[[Category: Fontecilla-Camps, J C]]

[[Category: Gruez, A]]

[[Category: Pignol, D]]

[[Category: Zeghouf, M]]

[[Category: Oxidoreductase]]