title: Crystal structure of SANOS, a bacterial nitric oxide synthase oxygenase protein from Staphylococcus aureus.
abstract: Prokaryotic genes related to the oxygenase domain of mammalian nitric oxide synthases (NOSs) have recently been identified. Although they catalyze the same reaction as the eukaryotic NOS oxygenase domain, their biological function(s) are unknown. In order to explore rationally the biochemistry and evolution of the prokaryotic NOS family, we have determined the crystal structure of SANOS, from methicillin-resistant Staphylococcus aureus (MRSA), to 2.4 A. Haem and S-ethylisothiourea (SEITU) are bound at the SANOS active site, while the intersubunit site, occupied by the redox cofactor tetrahydrobiopterin (H(4)B) in mammalian NOSs, has NAD(+) bound in SANOS. In common with all bacterial NOSs, SANOS lacks the N-terminal extension responsible for stable dimerization in mammalian isoforms, but has alternative interactions to promote dimer formation.
authors.affiliation: Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, Henry Wellcome Building of Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom.
authors.forename: Louise E
authors.initials: LE
authors.lastname: Bird
authors.forename: Jingshan
authors.initials: J
authors.lastname: Ren
authors.forename: Jiancheng
authors.initials: J
authors.lastname: Zhang
authors.forename: Neale
authors.initials: N
authors.lastname: Foxwell
authors.forename: Alastair R
authors.initials: AR
authors.lastname: Hawkins
authors.forename: Ian G
authors.initials: IG
authors.lastname: Charles
authors.forename: David K
authors.initials: DK
authors.lastname: Stammers
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002384:Catalysis; D002417:Cattle; D018360:Crystallography, X-Ray; D017931:DNA Primers; D019281:Dimerization; D006418:Heme / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D019001:Nitric Oxide Synthase / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013211:Staphylococcus aureus / Q000201:enzymology*
chemical_list: D017931:DNA Primers; D006418:Heme; D019001:Nitric Oxide Synthase