Molecular basis of the substrate specificity and the catalytic mechanism of citramalate synthase from Leptospira interrogans
文献类型：期刊论文
| 作者 | Ma, J; Zhang, P; Zhang, ZL; Zha, MW; Xu, H; Zhao, GP; Ding, JP |
| 刊名 | BIOCHEMICAL JOURNAL
 |
| 出版日期 | 2008 |
| 卷号 | 415期号:1页码:45-56 |
| 关键词 | aldol condensation catalytic mechanism citramalate synthase crystal structure feedback inhibition substrate specificity |
| 通讯作者 | Ding, JP (reprint author), Chinese Acad Sci, Shanghai Inst Biol Sci, Inst Plant Physiol & Ecol, Lab Microbial Mol Physiol, 300 Feng Lin Rd, Shanghai 200032, Peoples R China.,gpzhao@sibs.ac.cn |
| 英文摘要 | Leptospira interrogans is the causative agent for leptospirosis, a zoonotic disease of global importance. In contrast with most other micro-organisms, L. interrogans employs a pyruvate pathway to synthesize isoleucine and LiCMS (L. interrogans citramalate synthase) catalyses the first reaction of the pathway which converts pyruvate and acetyl-CoA into citramalate, thus making it an attractive target for the development of antibacterial agents. We report here the crystal structures of the catalytic domain of LiCMS and its complexes with substrates, and kinetic and mutagenesis studies of LiCMS, which together reveal the molecular basis of the high substrate specificity and the catalytic mechanism of LiCMS. The catalytic domain consists of a TIM barrel flanked by an extended C-terminal region. It forms a homodimer in the crystal structure, and the active site is located at the centre of the TIM barrel near the C-terminal ends of the P-strands and is composed of conserved residues of the P-strands of one subunit and the C-terminal region of the other. The substrate specificity of LiCMS towards pyruvate against other alpha-oxo acids is dictated primarily by residues Leu(81), Leu(104) and Tyr(144), which form a hydrophobic pocket to accommodate the C-2 -methyl group of pyruvate. The catalysis follows the typical aldol condensation reaction, in which Glu(146) functions as a catalytic base to activate the methyl group of acetyl-CoA to form an enolated acetyl-CoA intermediate and Arg(16) as a general acid to stabilize the intermediate. |
| 学科主题 | Biochemistry & Molecular Biology |
| 类目[WOS] | Biochemistry & Molecular Biology |
| 关键词[WOS] | ALPHA-ISOPROPYLMALATE SYNTHASE ; MYCOBACTERIUM-TUBERCULOSIS ; MALATE SYNTHASE ; ISOLEUCINE BIOSYNTHESIS ; SPIROCHETE-LEPTOSPIRA ; ANGSTROM RESOLUTION ; HEMORRHAGIC-FEVER ; CRYSTAL-STRUCTURE ; LEUCINE ; DENSITY |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000259788300006 |
| 版本 | 出版稿 |
| 源URL | [http://202.127.25.143/handle/331003/1489]  |
| 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 | Ma, J,Zhang, P,Zhang, ZL,et al. Molecular basis of the substrate specificity and the catalytic mechanism of citramalate synthase from Leptospira interrogans[J]. BIOCHEMICAL JOURNAL,2008,415(1):45-56. |
| APA | Ma, J.,Zhang, P.,Zhang, ZL.,Zha, MW.,Xu, H.,...&Ding, JP.(2008).Molecular basis of the substrate specificity and the catalytic mechanism of citramalate synthase from Leptospira interrogans.BIOCHEMICAL JOURNAL,415(1),45-56. |
| MLA | Ma, J,et al."Molecular basis of the substrate specificity and the catalytic mechanism of citramalate synthase from Leptospira interrogans".BIOCHEMICAL JOURNAL 415.1(2008):45-56. |
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