Uzelac Gordana, Miljkovic Marija, Lozo Jelena, Radulovic Zorica, Tosic Natasa, Kojic Milan
Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Serbia; Faculty of Agriculture, University of Belgrade, Serbia.
Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Serbia.
Microbiol Res. 2015 Oct;179:45-53. doi: 10.1016/j.micres.2015.06.011. Epub 2015 Jul 16.
The production of LsbB, leaderless class II bacteriocin, is encoded by genes (lsbB and lmrB) located on plasmid pMN5 in Lactococcus lactis BGMN1-5. Heterologous expression of the lsbB gene using the pAZIL vector (pAZIL-lsbB) in L. lactis subsp. cremoris MG7284 resulted in a significant reduction (more than 30 times) of bacteriocin LsbB expression. Subcloning and deletion experiments with plasmid pMN5 revealed that full expression of LsbB requires the presence of a complete transcription terminator located downstream of the lsbB gene. RNA stability analysis revealed that the presence of a transcription terminator increased the RNA stability by three times and the expression of LsbB by 30 times. The study of the influence of transcription terminator on the expression of other bacteriocin genes (lcnB, for lactococcin B production) indicated that this translational terminator likely functions in a lsbB-specific manner rather than in a general manner.
无领导II类细菌素LsbB的产生由乳酸乳球菌BGMN1 - 5中位于质粒pMN5上的基因（lsbB和lmrB）编码。使用pAZIL载体（pAZIL - lsbB）在乳酸乳球菌亚种cremoris MG7284中对lsbB基因进行异源表达，导致细菌素LsbB的表达显著降低（超过30倍）。对质粒pMN5进行亚克隆和缺失实验表明，LsbB的完全表达需要在lsbB基因下游存在一个完整的转录终止子。RNA稳定性分析表明，转录终止子的存在使RNA稳定性提高了三倍，LsbB的表达提高了30倍。对转录终止子对其他细菌素基因（用于产生乳球菌素B的lcnB）表达影响的研究表明，这种翻译终止子可能以lsbB特异性方式发挥作用，而不是以一般方式。
