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1mg2
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Revision as of 13:22, 28 September 2014 by OCA (Talk | contribs)
MUTATION OF ALPHA PHE55 OF METHYLAMINE DEHYDROGENASE ALTERS THE REORGANIZATION ENERGY AND ELECTRONIC COUPLING FOR ITS ELECTRON TRANSFER REACTION WITH AMICYANIN
1mg2 is a 16 chain structure with sequence from Paracoccus denitrificans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Methylamine dehydrogenase (MADH) possesses an alpha(2)beta(2) structure with each smaller beta subunit possessing a tryptophan tryptophylquinone (TTQ) prosthetic group. Phe55 of the alpha subunit is located where the substrate channel from the enzyme surface opens into the active site. Site-directed mutagenesis of alphaPhe55 has revealed roles for this residue in determining substrate specificity and binding monovalent cations at the active site. It is now shown that the alphaF55A mutation also increases the rate of the true electron transfer (ET) reaction from O-quinol MADH to amicyanin. The reorganization energy associated with the ET reaction is decreased from 2.3 to 1.8 eV. The electronic coupling associated with the ET reaction is decreased from 12 to 3 cm(-1). The crystal structure of alphaF55A MADH in complex with its electron acceptors, amicyanin and cytochrome c-551i, has been determined. Little difference in the overall structure is seen, relative to the native complex; however, there are significant changes in the solvent content of the active site and substrate channel. The crystal structure of alphaF55A MADH has also been determined with phenylhydrazine covalently bound to TTQ in the active site. Phenylhydrazine binding significantly perturbs the orientation of the TTQ rings relative to each other. The ET results are discussed in the context of the new and old crystal structures of the native and mutant enzymes.
Mutation of alphaPhe55 of methylamine dehydrogenase alters the reorganization energy and electronic coupling for its electron transfer reaction with amicyanin.,Sun D, Chen ZW, Mathews FS, Davidson VL Biochemistry. 2002 Nov 26;41(47):13926-33. PMID:12437349[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Sun D, Chen ZW, Mathews FS, Davidson VL. Mutation of alphaPhe55 of methylamine dehydrogenase alters the reorganization energy and electronic coupling for its electron transfer reaction with amicyanin. Biochemistry. 2002 Nov 26;41(47):13926-33. PMID:12437349
