Formation of an inverted repeat junction in the transposition of insertion sequence ISLC3 isolated from Lactobacillus casei.
An insertion sequence, ISLC3, of 1351 bp has been isolated from Lactobacillus casei. Formation of IS circles containing a 3 bp spacer (complete junction) or deletion of 25 bp at the left inverted repeat (IRL) between the abutted IS ends of the ISLC3 junction region (deleted junction) was also discovered in the lactobacilli and Escherichia coli system studied. We found that the promoter formed by the complete junction P(jun) was more active than that formed by the 25 bp deleted junction P(djun) or the indigenous promoter P(IRL). The corresponding transcription start sites for both promoter P(jun) and P(IRL) as well as P(djun) were subsequently determined using a primer extension assay. The activity of transposase OrfAB of ISLC3 was also assayed using an in vitro system. It was found that this transposase preferred to cleave a single DNA strand at the IRR over the IRL end in the transposition process, suggesting that attack of one end by the other was oriented from IRR to IRL.
Lo
Ta-Chun
TC
Institute of Molecular Medicine and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
Chen
Hung-Wen
HW
Institute of Molecular Medicine and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
Tsai
Yu-Kuo
YK
Institute of Molecular Medicine and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
Kuo
Yang-Cheng
YC
Institute of Molecular Medicine and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
Lin
Chao-Fen
CF
Institute of Molecular Medicine and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
Kuo
Ssu-Ying
SY
Institute of Molecular Medicine and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
Lin
Thy-Hou
TH
Institute of Molecular Medicine and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC.
D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D007780:Lacticaseibacillus casei / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D024363:Transcription Initiation Site; D019895:Transposases / Q000378:metabolism
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D019895:Transposases