1h4j

From Proteopedia

Revision as of 13:23, 30 October 2007

METHYLOBACTERIUM EXTORQUENS METHANOL DEHYDROGENASE D303E MUTANT

Overview

Two proteins specifically involved in methanol oxidation in the, methylotrophic bacterium Methylobacterium extorquens have been modified by, site-directed mutagenesis. Mutation of the proposed active site base, (Asp303) to glutamate in methanol dehydrogenase (MDH) gave an active, enzyme (D303E-MDH) with a greatly reduced affinity for substrate and with, a lower activation energy. Results of kinetic and deuterium isotope, studies showed that the essential mechanism in the mutant protein was, unchanged, and that the step requiring activation by ammonia remained rate, limiting. No spectrally detectable intermediates could be observed during, the reaction. The X-ray structure, determined to 3 A resolution, of, D303E-MDH showed that the position and coordination geometry of the Ca2+, ion in ... [(full description)]

About this Structure

1H4J is a [Protein complex] structure of sequences from [Methylobacterium extorquens] with CA and PQQ as [ligands]. Active as [Alcohol dehydrogenase (acceptor)], with EC number [1.1.99.8]. Structure known Active Sites: AC1, AC2, AC3, AC5, AC6, AC7 and AC8. Full crystallographic information is available from [OCA].

Reference

Site-directed mutagenesis and X-ray crystallography of the PQQ-containing quinoprotein methanol dehydrogenase and its electron acceptor, cytochrome c(L)., Afolabi PR, Mohammed F, Amaratunga K, Majekodunmi O, Dales SL, Gill R, Thompson D, Cooper JB, Wood SP, Goodwin PM, Anthony C, Biochemistry. 2001 Aug 21;40(33):9799-809. PMID:11502173

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