Molecular characterization of cytosolic cysteine synthase in Mimosa pudica
Molecular characterization of cytosolic cysteine synthase in Mimosa pudica
复制标题
含羞草胞质半胱氨酸合酶的分子特征
DOI：
10.1007/s10265-017-0986-5
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发表时间：
2018
影响因子：
2.8
通讯作者：
H. Oku
中科院分区：
文献类型：
--
作者：
Md. Harun Ur Rashid;H. Iwasaki;S. Oogai;M. Fukuta;S. Parveen;M. Hossain;T. Anai;H. Oku
在半胱氨酸和含羞草素的生物合成过程中，O-乙酰基-L-丝氨酸（OAS）是共同的底物。在O-乙酰丝氨酸（硫醇）裂解酶（OASTL，半胱氨酸合酶）存在下，OAS与硫化物反应生成半胱氨酸，而与3-羟基-4-吡啶酮（3 H4 P）反应生成含羞草素。酶OASTL可以催化Cys合成或Cys和含羞草碱两者。从mM中克隆了胞质OASTL的cDNA。pudica首次含有1，410 bp的核苷酸。从过表达的细菌细胞中纯化的蛋白产物仅产生Cys，但不产生含羞草碱，表明它是Cys特异性的。动力学研究表明，Cys生产的最佳pH和温度分别为6.5和50 °C。根据体外Cys测定，OAS的Km、Kcat和Kcat Km− 1测量值分别为159 ± 21 µM、33.56 s−1和211.07 mM− 1 s − 1，Na 2S的Km、Kcat和Kcat Km − 1测量值分别为252 ± 25 µM、32.99 s−1和130.91 mM− 1 s − 1。含羞草的Cy-OASTL对Cys的产生具有特异性，尽管它在硫同化和含羞草细胞内环境的还原网络中具有感觉作用。pudica。
In the cysteine and mimosine biosynthesis process,O-acetyl-l-serine (OAS) is the common substrate. In the presence ofO-acetylserine (thiol) lyase (OASTL, cysteine synthase) the reaction of OAS with sulfide produces cysteine, while with 3-hydroxy-4-pyridone (3H4P) produces mimosine. The enzyme OASTL can either catalyze Cys synthesis or both Cys and mimosine. A cDNA for cytosolic OASTL was cloned fromM. pudicafor the first time containing 1,410 bp nucleotides. The purified protein product from overexpressed bacterial cells produced Cys only, but not mimosine, indicating it is Cys specific. Kinetic studies revealed that pH and temperature optima for Cys production were 6.5 and 50 °C, respectively. The measured Km, Kcat, and Kcat Km−1values were 159 ± 21 µM, 33.56 s−1, and 211.07 mM−1s−1for OAS and 252 ± 25 µM, 32.99 s−1, and 130.91 mM−1s−1for Na2S according to thein vitroCys assay. The Cy-OASTL ofMimosa pudicais specific to Cys production, although it contains sensory roles in sulfur assimilation and the reduction network in the intracellular environment ofM. pudica.
影响因子：
--
作者：
J. Ponder;D. Case
通讯作者：
J. Ponder;D. Case
线粒体半胱氨酸合酶复合物调节植物中的 O-乙酰丝氨酸生物合成*
DOI：
10.1074/jbc.m112.372656
发表时间：
2012
期刊：
The Journal of Biological Chemistry
影响因子：
--
作者：
K. F. M;Schwarzlander;Sweetlove;Ratcliffe
通讯作者：
Ratcliffe