Crystallization (Comment) | Organism |
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crystal structure of flavocytochrome b2 solved at 3.0 A resolution by the method of multiple isomorphous replacement with anomalous scattering | Saccharomyces cerevisiae |
Organism | UniProt | Comment | Textmining |
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Saccharomyces cerevisiae | - |
- |
- |
Subunits | Comment | Organism |
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tetramer | - |
Saccharomyces cerevisiae |
Synonyms | Comment | Organism |
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flavocytochrome b2 | - |
Saccharomyces cerevisiae |
Cofactor | Comment | Organism | Structure |
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cytochrome | each subunit of the tetramer is composed of two domains, one binding a heme and the other an FMN prosthetic group. The cytochrome domain consists of residues 1 to 99 | Saccharomyces cerevisiae | |
FMN | each subunit of the tetramer is composed of two domains, one binding a heme and the other an FMN prosthetic group. The flavin binding domain contains a parallel beta8alpha8 barrel structure and is composed of residues 100 to 486. The FMN moiety, which is located at the C-terminal end of the central beta-barrel, is mostly sequestered from solvent. It forms hydrogen bond interactions with main- and side-chain atoms from six of the eight beta-strands. The interaction of Lys349 with atoms N-1 and O-2 of the flavin ring is probably responsible for stabilization of the anionic form of the flavin semiquinone and hydroquinone and enhancing the reactivity of atom N-5 toward sulfite. The binding of pyruvate at the active site in subunit 2 is stabilized by interaction of its carboxylate group with the side-chain atoms of Arg376 and Tyr143. Residues His373 and Tyr254 interact with the keto-oxygen atom and are involved in catalysis. In contrast, four water molecules occupy the substrate-binding site in subunit 1 and Tyr143 forms a hydrogen bond to the ordered heme propionate group. Otherwise the two flavin-binding domains are identical within experimental error | Saccharomyces cerevisiae |