鲜牛奶中副干酪乳杆菌隐蔽型质粒pMA3的全序列测定及功能分析  

Functional Analysis of a Cryptic Plasmid pMA3 in Lactobacillus paracasei Isolated from Fresh Milk

作　　者：郝彦玲[1] 翟征远[1] 尹胜[1] 李若愚[1] 黄莹[1] 陈栋[1] 王莹[1] 罗云波[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《农业生物技术学报》2008年第6期1031-1034,共4页Journal of Agricultural Biotechnology

基　　金：国家高技术研究与发展计划(863)项目(No.2006AA10Z317和No.2007AA10Z354);科技支撑项目(No.2006BAB04A06)资助

摘　　要：利用乳酸乳杆菌(Lactobacillus)选择性培养基SL,从鲜牛奶中分离1株携带2个天然质粒的副干酪乳杆菌(L.para-casei)MA3。通过寻找的ScaⅠ对未知小质粒pMA3进行酶切,产物连接载体pBK-CMV进行测序,全序列为5089bp,G+C含量为39.54%。进一步通过生物信息学分析质粒pMA3,该质粒编码4个开放阅读框,其中Rep3是复制起始蛋白,根据复制蛋白的同源性及其基因上游的连续正向重复序列证明pMA3属于pUCL-287θ-复制型质粒,该质粒GenBank登陆号为EU255257。Lactobacillus paracasei MA3, harboring two natural plasmids, was isolated fi＇om fresh milk using selective medium SL. In order to obtain the complete sequence, the unknown small plasmid pMA3 was digested by Sca I and ligated by vector pBK-CMV. The complete sequence ofpMA3 revealed to be 5 809 bp in length with GC content of 39.54%. The Bio-information revealed that pMA3 harbored four ORFs, one of them designated Rep3, which was replication initiation protein. Sequence analysis determined the highly homologous similarity of Rep3 protein and the tandem direct repeats, which demonstrated that pMA3 belonged to the pUCL-287 subfamily of them-type replicons. This plasmid has been deposited in GenBank under Accession No.EU255257.

关 键 词：副干酪乳杆菌 隐蔽型质粒 开放阅读框 功能分析 

分 类 号：S188[农业科学—农业基础科学]