Kinetic Analysis of Teicoplanin Glycosyltransferases and Acyltransferase Reveal Ordered Tailoring of Aglycone Scaffold to Reconstitute Mature Teicoplanin

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• 作者：Annaleise R. Howard-Jones ; Ryan G. Kruger ; Wei Lu ; Junhua Tao ; Catherine Leimkuhler ; Daniel Kahne ; Christopher T. Walsh
• 刊名：Journal of the American Chemical Society
• 出版年：2007
• 出版时间：August 22, 2007
• 年：2007
• 卷：129
• 期：33
• 页码：10082 - 10083
• 全文大小：431K
• 年卷期：v.129,no.33(August 22, 2007)
• ISSN：1520-5126

文摘

In the maturation of the glycopeptide antibiotic teicoplanin, two glycosyltransferases (tGtfA and tGtfB) and one acyltransferase (tAtf) act on the nascent scaffold to produce the final natural product. In this report, we present detailed kinetic characterization of each of these enzymes, demonstrating the ordered nature of these tailoring transformations. tGtfB acts first on the crosslinked peptide aglycone, adding either an N-acetylglucosamine or 2-aminoglucose moiety to the 4-position of the scaffold. The second glycosyltransferase, tGtfA, preferentially acts on this glycosylated scaffold to condense it with another molecule of N-acetylglucosamine. Although the acyltransferase tAtf is capable of N-acylating the free UDP sugar, UDP-2-acetylglucosamine, its catalytic efficiency is 100000-fold higher when acting on the 4-(2-aminoglucosyl)-teicoplanin scaffold, showing that it prefers to act on the aglycone-tethered sugar. This work expands on our previous studies of ordered tailoring of the vancomycin and chloroeremomycin scaffolds and demonstrates a distinct preference in ordering of the teicoplanin tailoring enzymes.