Effect of alanine-293 replacement on the activity, ATP binding, and editing of Escherichia coli leucyl-tRNA synthetase

	Effect of alanine-293 replacement on the activity, ATP binding, and editing of Escherichia coli leucyl-tRNA synthetase
	Chen, JF; Li, T; Wang, ED; Wang, YL
刊名	BIOCHEMISTRY
	2001
卷号	40 期号:5 页码:1144-1149
通讯作者	Wang, ED (reprint author), Chinese Acad Sci, Shanghai Inst Biol Sci, Inst Biochem & Cell Biol, State Key Lab Mol Biol, 320 Yue Yang Rd, Shanghai 200031, Peoples R China.,
英文摘要	Leucyl-tRNA synthetase (LeuRS) is a class I aminoacyl-tRNA synthetase that catalyzes leucylation of tRNA(Leu). Several mutants in the CP1 domain of Escherichia coli LeuRS were obtained by introduction of restriction endonuclease sites into its gene, leuS. Of these mutants, only LeuRS-A293F had decreased activity (46%) compared to the native enzyme. To investigate the effect of A293 on enzyme function, A293 was mutated to Y, G, I, R, or D. The mutants were impaired in activity and editing function to varying extents. The decrease in K-m values for three substrates showed that the binding of ATP to these mutants became much stronger. The inhibition of ATP binding to most of the mutants was also stronger. In particular, LeuRS-A293D had the lowest activity, the strongest ATP binding, and the most impaired editing function. A red shift of the fluorescence emission maximum of LeuRS-A293D indicated a less hydrophobic chromophore environment and a relatively more flexible dynamic conformation. The change in T-m of LeuRS-A293D was higher than that of all other substitutions. Evidence from sequence alignment and crystal structure of LeuRS from Thermus thermophilus shows that A293 was conserved as R (K) or A and is located at a small helix in the editing domain of the enzyme facing the active site. Hence, any amino acid substitution of A293 may affect the stability of the helix, which may lead to impaired editing function and aminoacylation activity and may be indirectly involved in ATP binding.
学科主题	Biochemistry & Molecular Biology
类目[WOS]	Biochemistry & Molecular Biology
关键词[WOS]	TRANSFER-RNA-SYNTHETASE ; GENETIC-CODE ; AMINOACYLATION ; RESOLUTION ; OVERPRODUCTION ; PURIFICATION ; RECOGNITION ; TRNA(LEU) ; EVOLUTION
收录类别	SCI
语种	英语
WOS记录号	WOS:000166842200002
内容类型	期刊论文
版本	出版稿
源URL	[http://202.127.25.143/handle/331003/2674]
专题	上海生化细胞研究所_上海生科院生化细胞研究所
推荐引用方式 GB/T 7714	Chen, JF,Li, T,Wang, ED,et al. Effect of alanine-293 replacement on the activity, ATP binding, and editing of Escherichia coli leucyl-tRNA synthetase[J]. BIOCHEMISTRY,2001,40(5):1144-1149.
APA	Chen, JF,Li, T,Wang, ED,&Wang, YL.(2001).Effect of alanine-293 replacement on the activity, ATP binding, and editing of Escherichia coli leucyl-tRNA synthetase.BIOCHEMISTRY,40(5),1144-1149.
MLA	Chen, JF,et al."Effect of alanine-293 replacement on the activity, ATP binding, and editing of Escherichia coli leucyl-tRNA synthetase".BIOCHEMISTRY 40.5(2001):1144-1149.