1vfr: Difference between revisions

We have solved the crystal structure of FRase I, the major NAD(P)H:FMN, oxidoreductase of Vibrio fischeri, by the multiple isomorphous replacement, method (MIR) at 1.8 A resolution with the conventional R factor of 0.187., The crystal structure of FRase I complexed with its competitive inhibitor, dicoumarol, has also been solved at 2.2 A resolution with the conventional, R factor of 0.161. FRase I is a homodimer, having one FMN cofactor per, subunit, which is situated at the interface of two subunits. The overall, fold can be divided into two domains; 80% of the residues form a rigid, core and the remaining, a small flexible domain. The overall core folding, is similar to those of an NADPH-dependent flavin reductase of Vibrio, harveyi (FRP) and the NADH oxidase of Thermus thermophilus (NOX) in spite, of the very low identity in amino acid sequences (10% with FRP and 21%, with NOX). 56% of alpha-carbons of FRase I core residues could be, superposed onto NOX counterparts with an r.m.s. distance of 1.2 A. The, remaining residues have relatively high B-values and may be essential for, defining the substrate specificity. Indeed, one of them, Phe124, was found, to participate in the binding of dicoumarol through stacking to one of the, rings of dicoumarol. Upon binding of dicoumarol, most of the exposed, re-face of the FMN cofactor is buried, which is consistent with the ping, pong bi bi catalytic mechanism.

1VFR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_fischeri Vibrio fischeri] with FMN as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Transferred_entry:_1.5.1.29 Transferred entry: 1.5.1.29], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.6.8.1 1.6.8.1] Structure known Active Sites: FM2 and FMN. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1VFR OCA].  

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