摘要
CRISPR-Cas系统为乳酸菌抵抗噬菌体等外源基因元件提供获得性免疫,利用生物信息学方法分析了CRISPR序列及cas基因在乳酸菌种间的同源性关系。利用生物信息学方法预测NCBI中已测序的部分乳酸菌所含CRISPRCas系统,并对重复序列和Cas蛋白序列进行系统发生学分析。结果显示,嗜热链球菌、德氏乳杆菌和瑞士乳杆菌标准菌株均含不同数目的 CRISPR-Cas系统,各类型的重复序列高度保守,Cas蛋白序列同源性较高。CRISPR-Cas系统的同源性与其亚型密切相关,而与菌种亲缘关系有较大差异,证明了CRISPR-Cas系统能够通过基因水平转移传播这一结论。
To analyze the homology CRISPR-Cas systems in Lactic acid bacteria. Bioinformatics method was used for predicting CRSPR-Cas system of Lactic acid bacteria that published in NCBI.There phylogenetic analysis was performed to investigate the level of conservation and divergence between the identified Lactic acid bacteria CRISPR immune systems using the repeats and universal Cas protein. Streptococcus thermophilus, Lactobacillus delbrueckfi subsp.bulgaricus and Lactobacillus helveticus all contain different number of CRISPR-Cas systems, the repeats of each type were highly conserved and the Cas proteins demonstrated high similarity.For homology analysis,repeats and Cas proteins showed high similarity with several individual species of distant relationships, which suggested that the CRISPRs of tested strains also had the characteristic of horizontal gene transfer（HGT）.
出处
《食品工业科技》
CAS
CSCD
北大核心
2016年第11期134-140,146,共8页
Science and Technology of Food Industry
基金
国家自然科学基金(31171717)
国家"863计划"(2012AA022108)
