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B6db references: 25404066

type Journal Article
authors Song H, Xu R, Guo Z
title Identification and characterization of a methionine γ-lyase in the calicheamicin biosynthetic cluster of Micromonospora echinospora
journal Chembiochem
Activity 4.4.1.11
Family 4.4.1.11
sel selected
ui 25404066
year (2015)
volume 16
number 1
pages 100-9
 
keywords biosynthesis; calicheamicins; enzyme catalysis; methionine gamma-lyase; protein structures
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.
last changed 2017/10/03 09:24

B6db references