2OHY

X-ray Crystal Structure of Tyrosine Aminomutase from streptomyces globisporus

Summary for 2OHY

• Entry DOI: 10.2210/pdb2ohy/pdb
• Descriptor: Tyrosine aminomutase (2 entities in total)
• Functional Keywords: mio; 4-methylideneimidizole-5-one, lyase, transferase
• Biological source: Streptomyces globisporus
• Total number of polymer chains: 2
• Total formula weight: 116625.80

Authors

Christianson, C.,Bruner, S. (deposition date: 2007-01-10, release date: 2007-06-12, Last modification date: 2024-11-06)

Primary citation

Christianson, C.V.,Montavon, T.J.,Van Lanen, S.G.,Shen, B.,Bruner, S.D.
The structure of L-tyrosine 2,3-aminomutase from the C-1027 enediyne antitumor antibiotic biosynthetic pathway
Biochemistry, 46:7205-7214, 2007

PubMed Abstract: 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.

PubMed: 17516659
DOI: 10.1021/bi7003685

Experimental method

X-RAY DIFFRACTION (2.5 Å)