The refined structure of the quinoprotein methanol dehydrogenase from Methylobacterium extorquens at 1.94 å
| Autor: | Christopher Anthony, Karl Harlos, Minakshi Ghosh, Colin C.F. Blake, Matthew G Goodwin |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Models
Molecular Semiquinone Protein Conformation Stereochemistry quinoprotein Molecular Sequence Data Coenzymes PQQ Cofactor methanol dehydrogenase Dehydrogenase Quinolones Crystallography X-Ray 010402 general chemistry 01 natural sciences 03 medical and health sciences Tetramer Structural Biology Computer Graphics Peptide bond Amino Acid Sequence Molecular Biology 030304 developmental biology 0303 health sciences Binding Sites PQQ Gram-Negative Aerobic Bacteria Molecular Structure biology Methanol dehydrogenase Chemistry Active site disulphide bridge biology.organism_classification 0104 chemical sciences Alcohol Oxidoreductases biology.protein Calcium Methylobacterium extorquens |
| Zdroj: | Structure. 3(2):177-187 |
| ISSN: | 0969-2126 |
| DOI: | 10.1016/s0969-2126(01)00148-4 |
| Popis: | Background: Methanol dehydrogenase (MDH) is a bacterial periplasmic quinoprotein; it has pyrrolo-quinoline quinone (PQQ) as its prosthetic group, requires Ca 2+ for activity and uses cytochrome c L as its electron acceptor. Low-resolution structures of MDH have already been determined. Results The structure of the α 2 β 2 tetramer of MDH from Methylobacterium extorquens has now been determined at 1.94 a with an R-factor of 19.85%. Conclusion The α -subunit of MDH has an eight-fold radial symmetry, with its eight β -sheets stabilized by a novel tryptophan docking motif. The PQQ in the active site is held in place by a coplanar tryptophan and by a novel disulphide ring formed between adjacent cysteines which are bonded by an unusual non-planar trans peptide bond. One of the carbonyl oxygens of PQQ is bonded to the Ca 2+ , probably facilitating attack on the substrate, and the other carbonyl oxygen is out of the plane of the ring, confirming the presence of the predicted free-radical semiquinone form of the prosthetic group. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|