Insights into the Branched-Chain Formation of Mycarose: Methylation Catalyzed by an (S)-Adenosylmethionine-Dependent Methyltransferase

Huawei Chen; Zongbao Zhao; Tina M Hallis; Zhihong Guo; Hung-Wen Liu

doi:10.1002/1521-3773(20010202)40:3<607::AID-ANIE607>3.0.CO;2-8

Insights into the Branched-Chain Formation of Mycarose: Methylation Catalyzed by an (S)-Adenosylmethionine-Dependent Methyltransferase

Angew Chem Int Ed Engl. 2001 Feb 2;40(3):607-610. doi: 10.1002/1521-3773(20010202)40:3<607::AID-ANIE607>3.0.CO;2-8.

Authors

Huawei Chen¹, Zongbao Zhao¹, Tina M Hallis¹, Zhihong Guo¹, Hung-Wen Liu¹

Affiliation

¹ Department of Chemistry, University of Minnesota Minneapolis, MN 55455, USA.

PMID: 29712024
DOI: 10.1002/1521-3773(20010202)40:3<607::AID-ANIE607>3.0.CO;2-8

Abstract

A C-methyltransferase involved in methyl-branch formation in sugars has been characterized for the first time. TylC3, an (S)-adenosylmethylthionine(AdoMet)-dependent enzyme, catalyzes the attachment of a methyl branch [Eq. (1)] in the biosynthesis of L-mycarose, an unusual sugar found in tylosin and as its O-3-methyl derivative in erythromycin. The C-3 methylation proceeds with inversion of configuration and does not require the assistance of any cofactors. The turnover rate is 1.4±0.1 min^-1 . TDP=thymidine-5'-dihydrogenphosphate.

Keywords: alkylation; biosynthesis; carbohydrates; enzyme catalysis; transferases.