Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Department of Biochemistry, Indian Institute of Science, CV Raman Road, Bengaluru 560012, India.
Biochem Biophys Res Commun. 2018 Nov 10;505(4):1057-1062. doi: 10.1016/j.bbrc.2018.09.185. Epub 2018 Oct 9.
Bacillus subtilis 168 EpsM (UniProt id P71063) has been electronically annotated as putative acetyltransferase in the UniProt database. The gene epsM was cloned and overexpressed in E. coli with an N-terminal GST tag. The purified fusion protein was shown by absorption spectroscopy, autoradiography and reverse phase HPLC to catalyse the conversion of UDP-2,4,6-trideoxy-2-acetamido-4-amino glucose to UDP-2,4,6-trideoxy-2,4-diacetamido glucose, commonly known as N,N'-diacetylbacillosamine, using acetyl coenzyme A as the donor substrate. His146 was shown by site-directed mutagenesis to be essential for acetyltransferase activity. It is hypothesized that EpsC (NAD dependent UDP GlcNAc 4,6-dehydratase), EpsN (PLP dependent aminotransferase) and EpsM, all of which are part of the eps operon, are involved in the biosynthesis of N,N'-diacetylbacillosamine.
枯草芽孢杆菌 168 EpsM（UniProt id P71063）在 UniProt 数据库中被电子注释为假定乙酰转移酶。epsM 基因被克隆并在大肠杆菌中过表达，带有 N 端 GST 标签。通过吸收光谱、放射自显影和反相 HPLC 显示，纯化的融合蛋白催化 UDP-2,4,6-三脱氧-2-乙酰氨基-4-氨基葡萄糖向 UDP-2,4,6-三脱氧-2,4-二乙酰氨基葡萄糖的转化，通常称为 N,N'-二乙酰杆菌素，乙酰辅酶 A 作为供体底物。通过定点突变显示 His146 对于乙酰转移酶活性是必需的。据推测，EpsC（NAD 依赖性 UDP GlcNAc 4,6-脱水酶）、EpsN（PLP 依赖性氨基转移酶）和 EpsM，它们都是 eps 操纵子的一部分，都参与了 N,N'-二乙酰杆菌素的生物合成。
