Lysine 190 Is the Catalytic Base in MenF, the Menaquinone-Specific Isochorismate Synthase from Escherichia coli: Implications for an Enzyme Family

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• 作者：Subramaniapillai Kolappan ; Jacque Zwahlen ; Rong Zhou ; James J. Truglio ; Peter J. Tonge ; Caroline Kisker
• 刊名：Biochemistry
• 出版年：2007
• 出版时间：January 30, 2007
• 年：2007
• 卷：46
• 期：4
• 页码：946 - 953
• 全文大小：278K
• 年卷期：v.46,no.4(January 30, 2007)
• ISSN：1520-4995

文摘

Menaquinone biosynthesis is initiated by the conversion of chorismate to isochorismate, areaction that is catalyzed by the menaquinone-specific isochorismate synthase, MenF. The catalyticmechanism of MenF has been probed using a combination of structural and biochemical studies, includingthe 2.5 Å structure of the enzyme, and Lys190 has been identified as the base that activates water fornucleophilic attack at the chorismate C2 carbon. MenF is a member of a larger family of Mg²⁺ dependentchorismate binding enzymes catalyzing distinct chorismate transformations. The studies reported hereextend the mechanism recently proposed for this enzyme family by He et al.: He, Z., Stigers Lavoie, K.D., Bartlett, P. A., and Toney, M. D. (2004) J. Am. Chem. Soc. 126, 2378-85.