Nyengaard N, Vogensen F K, Josephsen J
Royal Veterinary and Agricultural University, Department of Dairy and Food Science, Frederiksberg, Denmark.
Gene. 1993 Dec 22;136(1-2):371-2. doi: 10.1016/0378-1119(93)90499-s.
Two type-II restriction endonucleases have been purified from Lactococcus lactis subsp. cremoris W9 and W56, the strains isolated from a mixed Cheddar starter. Their characterization showed that LlaAI was an isoschizomer of MboI from Morexella bovis with the cleaving sequence, 5'/GATC-3', being sensitive to methylation of the adenine residue; LlaBI was an isoschizomer to SfcI from Streptococcus faceium with the cleaving sequence, 5'-C/TRYAG-3'. Both LlaAI and LlaBI restriction-modification (R-M) systems are encoded by the plasmids, respectively, pFW094 and pJW563, protecting the harboring strain against phage attack.
已从乳酸乳球菌乳脂亚种W9和W56中纯化出两种II型限制性内切酶，这两种菌株是从混合切达干酪发酵剂中分离得到的。对它们的特性分析表明，LlaAI是来自牛莫拉菌的MboI的同裂酶，切割序列为5'/GATC-3'，对腺嘌呤残基的甲基化敏感；LlaBI是来自面部链球菌的SfcI的同裂酶，切割序列为5'-C/TRYAG-3'。LlaAI和LlaBI限制性修饰（R-M）系统分别由质粒pFW094和pJW563编码，可保护宿主菌株免受噬菌体攻击。
