文章基本信息

标题：Mannosylglucosylglycerate biosynthesis in the deep-branching phylum Planctomycetes: characterization of the uncommon enzymes from Rhodopirellula baltica
本地全文：下载
作者：Sofia Cunha ; Ana Filipa d'Avó ; Ana Mingote 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2013
卷号：3
DOI：10.1038/srep02378
出版社：Springer Nature
摘要：The biosynthetic pathway for the rare compatible solute mannosylglucosylglycerate (MGG) accumulated by Rhodopirellula baltica , a marine member of the phylum Planctomycetes , has been elucidated. Like one of the pathways used in the thermophilic bacterium Petrotoga mobilis, it has genes coding for glucosyl-3-phosphoglycerate synthase (GpgS) and mannosylglucosyl-3-phosphoglycerate (MGPG) synthase (MggA). However, unlike Ptg. mobilis , the mesophilic R. baltica uses a novel and very specific MGPG phosphatase (MggB). It also lacks a key enzyme of the alternative pathway in Ptg. mobilis – the mannosylglucosylglycerate synthase (MggS) that catalyses the condensation of glucosylglycerate with GDP-mannose to produce MGG. The R. baltica enzymes GpgS, MggA, and MggB were expressed in E. coli and characterized in terms of kinetic parameters, substrate specificity, temperature and pH dependence. This is the first characterization of genes and enzymes for the synthesis of compatible solutes in the phylum Planctomycetes and for the synthesis of MGG in a mesophile.