Download MendeleyIdentification and Characterization of a Methionine gamma-Lyase in the Calicheamicin Biosynthetic Cluster of Micromonospora echinospora
Song, H., Xu, R., Guo, Z.(2015) Chembiochem 16: 100-109
- PubMed: 25404066
- DOI: https://doi.org/10.1002/cbic.201402489
- Primary Citation of Related Structures:
4U1T, 4U2H - PubMed Abstract:
CalE6 is a previously uncharacterized protein involved in the biosynthesis of calicheamicins in Micromonospora echinospora. It is a pyridoxal-5'-phosphate-dependent enzyme and exhibits high sequence homology to cystathionine γ-lyases and cystathionine γ-synthases. However, it was found to be active towards methionine and to convert this amino acid into α-ketobutyrate, ammonium, and methanethiol. The crystal structure of the cofactor-bound holoenzyme was resolved at 2.0 Å; it contains two active site residues, Gly105 and Val322, specific for methionine γ-lyases. Modeling of methionine into the active site allows identification of the active site residues responsible for substrate recognition and catalysis. These findings support that CalE6 is a putative methionine γ-lyase producing methanethiol as a building block in biosynthesis of calicheamicins.
Organizational Affiliation:
Department of Chemistry and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong).
