Rubens C E, Heggen L M, Kuypers J M
Division of Infectious Disease, Children's Hospital and Medical Center, Seattle, Washington.
J Bacteriol. 1989 Oct;171(10):5531-5. doi: 10.1128/jb.171.10.5531-5535.1989.
A 1,442-base-pair (bp) insertion sequence (IS861) was identified in the type III group B streptococcal (GBS) strain COH-1. It is flanked by 26-bp imperfect inverted repeats and contains two open reading frames, 1 and 2, encoding 141- and 277-amino-acid proteins, respectively. A 3-bp target sequence, ACA, is duplicated and flanks each inverted repeat. IS861 shares greater than 30% homology with IS3 and IS150 of Escherichia coli, primarily in the region of their putative transposases. Northern (RNA) analysis revealed that RNA is actively transcribed in vivo by IS861 and 17- and 36-kilodalton proteins were synthesized in E. coli maxicell assays. Multiple copies of IS861 were observed throughout the chromosome of COH-1, and one of the copies is located near genes involved in GBS capsule synthesis. IS861 is the first insertion sequence identified in GBS. Its role in GBS and the significance of its relationship to the phylogenetically similar insertion sequences typified by IS150 and IS3 of E. coli are unknown.
在III型B族链球菌（GBS）菌株COH-1中鉴定出一个1442个碱基对（bp）的插入序列（IS861）。它两侧是26 bp的不完全反向重复序列，包含两个开放阅读框，即1和2，分别编码141个和277个氨基酸的蛋白质。一个3 bp的靶序列ACA被复制并位于每个反向重复序列的两侧。IS861与大肠杆菌的IS3和IS150具有超过30%的同源性，主要在其假定转座酶区域。Northern（RNA）分析显示，IS861在体内可活跃转录RNA，并且在大肠杆菌的最大细胞分析中合成了17 kDa和36 kDa的蛋白质。在COH-1的整个染色体上观察到多个IS861拷贝，其中一个拷贝位于参与GBS荚膜合成的基因附近。IS861是在GBS中鉴定出的第一个插入序列。其在GBS中的作用以及它与以大肠杆菌的IS150和IS3为代表的系统发育相似插入序列之间关系的意义尚不清楚。
