|
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 |
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