|
type |
Journal Article |
authors |
Qin Z, Yan Q, Ma Q, Jiang Z |
title |
Crystal structure and characterization of a novel L-serine ammonia-lyase from Rhizomucor miehei |
journal |
Biochem Biophys Res Commun |
Activity |
4.3.1.17 |
Family |
4.3.1.17.a |
sel |
selected |
ui |
26367174 |
year |
(2015) |
volume |
466 |
number |
3 |
pages |
431-7 |
| |
keywords |
Crystal structure; Pyridoxal-5′-phosphate; Rhizomucor miehei; Serine dehydratase; l-Serine ammonia-lyase; β-Elimination enzymes |
abstract |
L-serine ammonia-lyase, as a member of the β-family of pyridoxal-5'-phosphate (PLP) dependent enzymes, catalyzes the conversion of L-serine (L-threonine) to pyruvate (α-ketobutyrate) and ammonia. The crystal structure of L-serine ammonia-lyase from Rhizomucor miehei (RmSDH) was solved at 1.76 Å resolution by X-ray diffraction method. The overall structure of RmSDH had the characteristic β-family PLP dependent enzyme fold. It consisted of two distinct domains, both of which show the typical open twisted α/β structure. A PLP cofactor was located in the crevice between the two domains, which was attached to Lys52 by a Schiff-base linkage. Unique residue substitutions (Gly78, Pro79, Ser146, Ser147 and Thr312) were discovered at the catalytic site of RmSDH by comparison of structures of RmSDH and other reported eukaryotic L-serine ammonia-lyases. Optimal pH and temperature of the purified RmSDH were 7.5 and 40 °C, respectively. It was stable in the pH range of 7.0-9.0 and at temperatures below 40 °C. This is the first crystal structure of a fungal L-serine ammonia-lyase. It will be useful to study the catalytic mechanism of β-elimination enzymes and will provide a basis for further enzyme engineering. |
last changed |
2017/07/25 16:27 |
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