Nesvera J, Hochmannová J, Pátek M
Institute of Microbiology, Academy of Sciences of the Czech Republic, Praha, Czech Republic.
FEMS Microbiol Lett. 1998 Dec 15;169(2):391-5. doi: 10.1111/j.1574-6968.1998.tb13345.x.
The streptomycin/spectinomycin resistance determinant of the 29-kb plasmid pCG4 from Corynebacterium glutamicum was found to be a part of a typical class 1 integron. The sequence analysis revealed that the integron (designated InCg) identified in this Gram-positive bacterium is almost identical to the integron InC present on the plasmid pSA1700 from the Gram-negative bacterium Pseudomonas aeruginosa. Differences in only two base pairs were found in the 3.8-kb sequence. One base substitution (G-->C) is present in the streptomycin/spectinomycin resistance determinant which is thus identical to the aadA2a gene from the integron In6 of the broad-host-range plasmid pSa. The other one (C-->G) is present in the extended -10 region of the integron promoter involved in expression of the antibiotic resistance gene. It was shown that this novel version of the integron promoter displays five times higher activity in both C. glutamicum and Escherichia coli than the original one.
发现来自谷氨酸棒杆菌的29 kb质粒pCG4的链霉素/壮观霉素抗性决定簇是典型1类整合子的一部分。序列分析表明，在这种革兰氏阳性细菌中鉴定出的整合子（命名为InCg）与来自革兰氏阴性细菌铜绿假单胞菌的质粒pSA1700上的整合子InC几乎相同。在3.8 kb序列中仅发现两个碱基对的差异。一个碱基替换（G→C）存在于链霉素/壮观霉素抗性决定簇中，因此与来自广泛宿主范围质粒pSa的整合子In6的aadA2a基因相同。另一个（C→G）存在于参与抗生素抗性基因表达的整合子启动子的扩展 -10区域中。结果表明，这种新型整合子启动子在谷氨酸棒杆菌和大肠杆菌中的活性比原始启动子高五倍。
