State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
Enzyme Microb Technol. 2013 Aug 15;53(3):165-9. doi: 10.1016/j.enzmictec.2013.03.002. Epub 2013 Mar 15.
Transposition insertional mutagenesis of the insertion sequences (IS elements) was discovered for the first time in Acidithiobacillus caldus (A. caldus), when A. caldus MTH-04 hsdM (type I restriction-modification system M-subunit) mutant was constructed by electroporation of a suicide plasmid. The IS element, specifically inserting into hsdM gene, was analyzed, identified, and named ISAtc2. The transposition frequency of ISAtc2 was ranged from 4% to 7%, and no reverse mutation occurred in the mutants after 50 generations of proliferation without selective pressure. These results revealed that transposition of IS elements on A. caldus chromosome could regulate the gene expression and metabolic pathways by gene inactivation, gene loss and gene acquisition. Therefore, the transposition of IS elements in A. caldus may be an important and unique regulation mechanism for adaptation to the living condition.
转座插入突变的插入序列（IS 元件）是首次在嗜酸硫杆菌（A. caldus）中发现的，当时通过电穿孔自杀质粒构建了嗜酸硫杆菌 MTH-04 hsdM（I 型限制修饰系统 M 亚基）突变体。分析、鉴定并命名了特异性插入 hsdM 基因的 ISAtc2 元件。ISAtc2 的转座频率在 4%到 7%之间，在没有选择压力的情况下，经过 50 代增殖后，突变体中没有发生回复突变。这些结果表明，IS 元件在 A. caldus 染色体上的转座可以通过基因失活、基因缺失和基因获得来调节基因表达和代谢途径。因此，IS 元件在 A. caldus 中的转座可能是适应生存条件的一个重要和独特的调节机制。
