铜绿假单胞菌PAO1株基因组中2个SOS盒序列的初步鉴定

Primary identification on sequences of 2 SOS boxes in genome of Pseudomonas aeruginosa PAO1

目的鉴定铜绿假单胞菌(Pseudomonas aeruginosa,PA)PAO1株基因组中的SOS盒序列。方法挑选铜绿假单胞菌PAO1株基因组中16个可能含有SOS盒序列的DNA片段,经PCR扩增后,用纯化的LexA表达蛋白做凝胶滞后实验;将获得的2个阳性DNA片段进一步用DNaseⅠ足纹法进行LexA蛋白结合序列即SOS盒的鉴定;分析所获得的2个SOS盒中的回文序列,以此回文序列在PAO1基因组中进行检索,初步分析出可能的SOS盒序列和可能的调控基因。结果通过DNaseⅠ足纹法初步鉴定了PAO1基因组中2个SOS盒序列,即位于基因组4 052 647～4 052 662 bp位置的CTGTCTACTTATACAG序列和5 349 888～5 349 903 bp位置的CTGTATAAATAACCAG序列,分析其回文结构为"CTG…CAG",以此回文序列在基因组中进行检索,共获得了10个候选的SOS盒序列。结论初步证实了PAO1基因组中的2个SOS盒,并获得了10条SOS盒候选序列。

Objective To identify the sequences of the SOS boxes in genome of Pseudomonas aeruginosa PAO1. Methods Sixteen DNA fragments containing potential SOS box in genome of PAO1 were amplified with PCR, and then fragments were primary identified through electrophoretic mobility shift assay （EMSA） with purified LexA expressing protein. The SOS boxes sequence in the 2 positive fragments were identified by DNase I foot printing testing, and the palindrome sequence in the 2 SOS boxes was analyzed. Based on the palindrome sequence, the putative SOS boxes and theirs regulated genes were primary searched in Pseudomonas aeruginosa PAO1. Results Two SOS boxes sequence in the genome of PAO1 were identified by DNase ｜ foot printing test, they are＂ CTGTCTACTTATACAG＂ sequence in the location of 4 052 647 to 4 052 662 bp and ＂CTGTCTACTTATACAG＂ sequence in the location of 5 349 888 to 5 349 903 bp in the genome of PAO1. And the palindrome sequence of the SOS boxes is ＂CTG＂.CAG＂. Based on this sequence, 10 putative SOS boxes and their regulated genes were searched. Conclusion Two SOS boxes sequences in genome of PAO1 are primary identified, and 10 putative SOS boxes are selected in this study.