3k4j

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Pyranose 2-oxidase H450Q mutantPyranose 2-oxidase H450Q mutant

Structural highlights

3k4j is a 1 chain structure with sequence from Trametes ochracea. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q7ZA32_TRAOC

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Pyranose 2-oxidase from Trametes multicolor is a 270 kDa homotetrameric enzyme that participates in lignocellulose degradation by wood-rotting fungi and oxidizes a variety of aldopyranoses present in lignocellulose to 2-ketoaldoses. The active site in pyranose 2-oxidase is gated by a highly conserved, conformationally degenerate loop (residues 450-461), with a conformer ensemble that can accommodate efficient binding of both electron-donor substrate (sugar) and electron-acceptor substrate (oxygen or quinone compounds) relevant to the sequential reductive and oxidative half-reactions, respectively. To investigate the importance of individual residues in this loop, a systematic mutagenesis approach was used, including alanine-scanning, site-saturation and deletion mutagenesis, and selected variants were characterized by biochemical and crystal-structure analyses. We show that the gating segment ((454)FSY(456)) of this loop is particularly important for substrate specificity, discrimination of sugar substrates, turnover half-life and resistance to thermal unfolding, and that three conserved residues (Asp(452), Phe(454) and Tyr(456)) are essentially intolerant to substitution. We furthermore propose that the gating segment is of specific importance for the oxidative half-reaction of pyranose 2-oxidase when oxygen is the electron acceptor. Although the position and orientation of the slow substrate 2-deoxy-2-fluoro-glucose when bound in the active site of pyranose 2-oxidase variants is identical to that observed earlier, the substrate-recognition loop in F454N and Y456W displays a high degree of conformational disorder. The present study also lends support to the hypothesis that 1,4-benzoquinone is a physiologically relevant alternative electron acceptor in the oxidative half-reaction.

Importance of the gating segment in the substrate-recognition loop of pyranose 2-oxidase.,Spadiut O, Tan TC, Pisanelli I, Haltrich D, Divne C FEBS J. 2010 Jul;277(13):2892-909. Epub 2010 Jun 2. PMID:20528921[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Spadiut O, Tan TC, Pisanelli I, Haltrich D, Divne C. Importance of the gating segment in the substrate-recognition loop of pyranose 2-oxidase. FEBS J. 2010 Jul;277(13):2892-909. Epub 2010 Jun 2. PMID:20528921 doi:10.1111/j.1742-4658.2010.07705.x

3k4j, resolution 2.00Å

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OCA