Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow region.
Extremophiles. 2011 Nov;15(6):653-63. doi: 10.1007/s00792-011-0396-x. Epub 2011 Oct 5.
The genes of ectoine biosynthesis pathway were identified in six species of aerobic, slightly halophilic bacteria utilizing methane, methanol or methylamine. Two types of ectoine gene cluster organization were revealed in the methylotrophs. The gene cluster ectABC coding for diaminobutyric acid (DABA) acetyltransferase (EctA), DABA aminotransferase (EctB) and ectoine synthase (EctC) was found in methanotrophs Methylobacter marinus 7C and Methylomicrobium kenyense AMO1(T). In methanotroph Methylomicrobium alcaliphilum ML1, methanol-utilizers Methylophaga thalassica 33146(T) , Methylophaga alcalica M8 and methylamine-utilizer Methylarcula marina h1(T), the genes forming the ectABC-ask operon are preceded by ectR, encoding a putative transcriptional regulatory protein EctR. Phylogenetic relationships of the Ect proteins do not correlate with phylogenetic affiliation of the strains, thus implying that the ability of methylotrophs to produce ectoine is most likely the result of a horizontal transfer event.
在利用甲烷、甲醇或甲胺的六种需氧、轻度嗜盐细菌中鉴定出了胞外嘧啶生物合成途径的基因。在甲基营养菌中发现了两种类型的胞嘧啶基因簇组织。编码二氨基丁酸（DABA）乙酰基转移酶（EctA）、DABA 氨基转移酶（EctB）和胞嘧啶合酶（EctC）的基因簇 ectABC 在甲烷营养菌 Methylobacter marinus 7C 和 Methylomicrobium kenyense AMO1(T) 中被发现。在甲烷营养菌 Methylomicrobium alcaliphilum ML1 中，甲醇利用菌 Methylophaga thalassica 33146(T)、Methylophaga alcalica M8 和甲胺利用菌 Methylarcula marina h1(T) 中，形成 ectABC-ask 操纵子的基因之前是 ectR，编码一个假定的转录调节蛋白 EctR。Ect 蛋白的系统发育关系与菌株的系统发育归属不相关，这表明甲基营养菌产生胞嘧啶的能力很可能是水平转移事件的结果。
