1qyc
From Proteopedia
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Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases, and their relationship to isoflavone reductases
Overview
Despite the importance of plant lignans and isoflavonoids in human health, protection (e.g. for both treatment and prevention of onset of various, cancers) as well as in plant biology (e.g. in defense functions and in, heartwood development), systematic studies on the enzymes involved in, their biosynthesis have only recently begun. In this investigation, three, NADPH-dependent aromatic alcohol reductases were comprehensively studied, namely pinoresinol-lariciresinol reductase (PLR), phenylcoumaran benzylic, ether reductase (PCBER), and isoflavone reductase (IFR), which are, involved in central steps to the various important bioactive lignans and, isoflavonoids. Of particular interest was in determining how differing, regio- and enantiospecificities are achieved with the different enzymes, despite each apparently going through similar enone intermediates., Initially, the three-dimensional x-ray crystal structures of both PLR_Tp1, and PCBER_Pt1 were solved and refined to 2.5 and 2.2 A resolutions, respectively. Not only do they share high gene sequence similarity, but, their structures are similar, having a continuous alpha/beta NADPH-binding, domain and a smaller substrate-binding domain. IFR (whose crystal, structure is not yet obtained) was also compared (modeled) with PLR and, PCBER and was deduced to have the same overall basic structure. The basis, for the distinct enantio-specific and regio-specific reactions of PCBER, PLR, and IFR, as well as the reaction mechanism and participating residues, involved (as identified by site-directed mutagenesis), are discussed.
About this Structure
1QYC is a Single protein structure of sequence from Pinus taeda. Full crystallographic information is available from OCA.
Reference
Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases and their relationship to isoflavone reductases., Min T, Kasahara H, Bedgar DL, Youn B, Lawrence PK, Gang DR, Halls SC, Park H, Hilsenbeck JL, Davin LB, Lewis NG, Kang C, J Biol Chem. 2003 Dec 12;278(50):50714-23. Epub 2003 Sep 16. PMID:13129921
Page seeded by OCA on Sat Nov 24 21:46:32 2007
