2amo
From Proteopedia
Loose Dimer of a Bacillus subtilis Nitric Oxide Synthase
Overview
Cooperativity among ligand binding, subunit association, and protein folding has implications for enzyme regulation as well as protein aggregation events associated with disease. The binding of substrate l-arginine or cofactor tetrahydrobiopterin converts nitric oxide synthases (NOSs) from a "loose dimer", with an exposed active center and higher sensitivity to proteolysis, to a "tight dimer" competent for catalysis. The crystallographic structure of the Bacillus subtilis NOS loose dimer shows an altered association state with severely destabilized subdomains. Ligand binding or heme reduction converts loose dimers to tight dimers in solution and crystals. Mutations at key positions in the dimer interface that distinguish prokaryotic from eukaryotic NOSs affect the propensity to form loose dimers. The loose dimer structure indicates that non-native interactions can mediate subunit association in NOS.
About this Structure
2AMO is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Structure of a loose dimer: an intermediate in nitric oxide synthase assembly., Pant K, Crane BR, J Mol Biol. 2005 Sep 30;352(4):932-40. PMID:16126221 Page seeded by OCA on Sat May 3 19:13:36 2008
