Department of Genetics, University of Georgia, Athens, GA, 30602, USA.
J Ind Microbiol Biotechnol. 2013 Dec;40(12):1443-8. doi: 10.1007/s10295-013-1345-8. Epub 2013 Oct 1.
Caldicellulosiruptor bescii is an anaerobic thermophilic bacterium of special interest for use in the consolidated bioprocessing of plant biomass to biofuels. In the course of experiments to engineer pyruvate metabolism in C. bescii, we isolated a mutant of C. bescii that contained an insertion in the L-lactate dehydrogenase gene (ldh). PCR amplification and sequencing of the ldh gene from this mutant revealed a 1,609-bp insertion that contained a single open reading frame of 479 amino acids (1,440 bp) annotated as a hypothetical protein with unknown function. The ORF is flanked by an 8-base direct repeat sequence. Bioinformatic analysis indicated that this ORF is part of a novel transposable element, ISCbe4, which is only intact in the genus Caldicellulosiruptor, but has ancient relatives that are present in degraded (and previously unrecognized) forms across many bacterial and archaeal clades.
贝氏考克氏菌是一种厌氧嗜热细菌，特别适合用于植物生物质的联合生物加工以生产生物燃料。在对贝氏考克氏菌丙酮酸代谢进行工程改造的实验过程中，我们分离到一株含有 L-乳酸脱氢酶基因（ldh）插入突变的贝氏考克氏菌突变株。对该突变株 ldh 基因的 PCR 扩增和测序显示，存在一个 1609bp 的插入片段，其中包含一个 479 个氨基酸（1440bp）的单一开放阅读框，注释为具有未知功能的假定蛋白。该 ORF 两侧为 8 个碱基的直接重复序列。生物信息学分析表明，该 ORF 是一个新型转座元件 ISCbe4 的一部分，该元件仅在 Caldicellulosiruptor 属中完整存在，但在许多细菌和古菌类群中以降解（和以前未被识别）的形式存在其古老的同源物。
