Crystal Structure Determination of a Flavoprotein FP390 from a Luminescent Bacterium, Photobacterium phosphoreum1

DOI PubMed

Search this article

Description

The three-dimensional structure of a flavoprotein, FP390, purified from a luminescent bacterium, Photobacterium phosphoreum, has been determined at 3 A resolution by X-ray crystallography. Crystallographic refinements of the structural model have led to an R-factor of 0.24 for the intensity data between 6 to 3 A resolution collected with synchrotron radiation. It was found that a homodimer of the FP390 molecules related by a non-crystallographic 2-fold axis is comprised in the asymmetric unit. Two homodimers are arranged around a crystallographic 2-fold axis to form a tetrameric assembly. The monomer molecule of FP390, to which two molecules of the flavin cofactor (Q-flavin) are bound, consists of a seven-stranded parallel beta-sheet which forms a half of the beta-barrel structure and seven alpha-helices which surround one side of the beta-barrel. We suggest that the reason why the Q-flavin sample prepared from FP390 is always a mixture of two components is connected with the fact that the monomer molecules has two flavin binding sites, at the dimer interface and at the molecular surface.

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top