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124 a.a.
373 a.a.
 RCH(2)NH(2) |
+ |
H(2)O |
+ |
acceptor |
= |
 RCHO |
+ |
NH(3) |
+ |
reduced acceptor |
|---|
Key reference
DOI no: 10.1021/bi00155a036 Biochemistry 31:9789-9795 (1992) PubMed id: 1390754
Active site structure of methylamine dehydrogenase: hydrazines identify C6 as the reactive site of the tryptophan-derived quinone cofactor. E.G.Huizinga, B.A.van Zanten, J.A.Duine, J.A.Jongejan, F.Huitema, K.S.Wilson, W.G.Hol. ABSTRACT
To identify the reactive part of the orthoquinone function of the tryptophan-derived cofactor found in methylamine dehydrogenase (MADH), we have determined the crystal structures of MADH from Thiobacillus versutus inhibited by methylhydrazine and (2,2,2-trifluoroethyl)hydrazine. Extra electron density attached to C6 of the tryptophyl tryptophanquinone cofactor shows that this atom and not C7 is the reactive part of the ortho-quinone moiety. The density retained after hydrazine inhibition is much less extensive than expected, however, suggesting that partial breakdown of the inhibitors after reaction with the cofactor may take place. A detailed description is presented of the cofactor environment in an improved model of MADH which now includes information from the recently determined gene sequence of the cofactor-containing subunit [Ubbink, M., van Kleef, M.A.G., Kleinjan, D., Hoitink, C.W.G., Huitema, F., Beintema, J.J., Duine, J.A., & Canters, G.W. (1991) Eur. J. Biochem. 202, 1003-1012]. We hypothesize that Asp76 is responsible for proton abstraction from the alpha-carbon of the substrate during catalysis.
Literature references that cite this PDB file's key reference
PubMed id Reference
11733518 Y.Wang, D.Sun, and V.L.Davidson (2002).
Use of indirect site-directed mutagenesis to alter the substrate specificity of methylamine dehydrogenase.J Biol Chem, 277, 4119-4122.
11717396 S.Datta, Y.Mori, K.Takagi, K.Kawaguchi, Z.W.Chen, T.Okajima, S.Kuroda, T.Ikeda, K.Kano, K.Tanizawa, and F.S.Mathews (2001).
Structure of a quinohemoprotein amine dehydrogenase with an uncommon redox cofactor and highly unusual crosslinking.Proc Natl Acad Sci U S A, 98, 14268-14273.
PDB code: 1jju
10985763 Z.Zhu, D.Sun, and V.L.Davidson (2000).
Conversion of methylamine dehydrogenase to a long-chain amine dehydrogenase by mutagenesis of a single residue.Biochemistry, 39, 11184-11186.
9748238 G.Labesse, D.Ferrari, Z.W.Chen, G.L.Rossi, V.Kuusk, W.S.McIntire, and F.S.Mathews (1998).
Crystallographic and spectroscopic studies of native, aminoquinol, and monovalent cation-bound forms of methylamine dehydrogenase from Methylobacterium extorquens AM1.J Biol Chem, 273, 25703-25712.
7876189 S.L.Edwards, V.L.Davidson, Y.L.Hyun, and P.T.Wingfield (1995).
Spectroscopic evidence for a common electron transfer pathway for two tryptophan tryptophylquinone enzymes.J Biol Chem, 270, 4293-4298. The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.
