1an9
From Proteopedia
D-AMINO ACID OXIDASE COMPLEX WITH O-AMINOBENZOATE
Overview
As an extension of our recent X-ray crystallographic determination of the tertiary structure of D-amino acid oxidase (DAO) [Mizutani, H. et al. (1996) J. Biochem. 120, 14-17], we solved the crystal structure of the complex of DAO with a substrate analog, o-aminobenzoate (OAB). The alignment between flavin and OAB in the crystal structure of the complex is consistent with charge-transfer interaction through the overlap between the highest occupied molecular orbital of OAB and the lowest unoccupied molecular orbital of flavin. Starting with the atomic coordinates of this complex as the initial model, we carried out molecular mechanics simulation for the DAO-D-leucine complex and thus obtained a model for the enzyme-substrate complex. According to the enzyme-substrate complex model, the alpha-proton is pointed toward N(5) of flavin while the lone-pair of the substrate amino group can approach C(4a) of flavin within an interacting distance. This model as well as DAO-OAB complex enables the evaluation of the substrate-flavin interaction prior to electron transfer from the substrate to flavin and provides two possible mechanisms for the reductive-half reaction of DAO, i.e., the electron-proton-electron transfer mechanism and the ionic mechanism.
About this Structure
1AN9 is a Single protein structure of sequence from Sus scrofa. Full crystallographic information is available from OCA.
Reference
Structural and mechanistic studies on D-amino acid oxidase x substrate complex: implications of the crystal structure of enzyme x substrate analog complex., Miura R, Setoyama C, Nishina Y, Shiga K, Mizutani H, Miyahara I, Hirotsu K, J Biochem. 1997 Oct;122(4):825-33. PMID:9399588 Page seeded by OCA on Fri May 2 10:28:29 2008
