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B6db references: 26367174

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 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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