2ohy
|
X-ray Crystal Structure of Tyrosine Aminomutase from streptomyces globisporus
OverviewOverview
The SgcC4 l-tyrosine 2,3-aminomutase (SgTAM) catalyzes the formation of, (S)-beta-tyrosine in the biosynthetic pathway of the enediyne antitumor, antibiotic C-1027. SgTAM is homologous to the histidine ammonia lyase, family of enzymes whose activity is dependent on the, methylideneimidazole-5-one (MIO) cofactor. Unlike the lyase enzymes, SgTAM, catalyzes additional chemical transformations resulting in an overall, stereospecific 1,2-amino shift in the substrate l-tyrosine to generate, (S)-beta-tyrosine. Previously, we provided kinetic, spectroscopic, and, mutagenesis data supporting the presence of MIO in the active site of, SgTAM [Christenson, S. D.; Wu, W.; Spies, A.; Shen, B.; and Toney, M. D., (2003) Biochemistry 42, 12708-12718]. Here we report the first X-ray, crystal structure of an MIO-containing aminomutase, SgTAM, and confirm the, structural homology of SgTAM to ammonia lyases. Comparison of the, structure of SgTAM to the l-tyrosine ammonia lyase from Rhodobacter, sphaeroides provides insight into the structural basis for aminomutase, activity. The results show that SgTAM has a closed active site well suited, to retain ammonia and minimize the formation of lyase elimination, products. The amino acid determinants for substrate recognition and, catalysis can be predicted from the structure, setting the framework for, detailed mechanistic investigations.
About this StructureAbout this Structure
2OHY is a Single protein structure of sequence from Streptomyces globisporus. Active as Tyrosine 2,3-aminomutase, with EC number 5.4.3.6 Full crystallographic information is available from OCA.
ReferenceReference
The Structure of l-Tyrosine 2,3-Aminomutase from the C-1027 Enediyne Antitumor Antibiotic Biosynthetic Pathway(,)., Christianson CV, Montavon TJ, Lanen SG, Shen B, Bruner SD, Biochemistry. 2007 Jun 19;46(24):7205-7214. Epub 2007 May 22. PMID:17516659
Page seeded by OCA on Wed Jan 23 12:03:20 2008