Lunnen K D, Barsomian J M, Camp R R, Card C O, Chen S Z, Croft R, Looney M C, Meda M M, Moran L S, Nwankwo D O
New England Biolabs, Inc., Beverly, MA 01915.
Gene. 1988 Dec 25;74(1):25-32. doi: 10.1016/0378-1119(88)90242-9.
We have cloned into Escherichia coli the genes for 38 type-II bacterial modification methyltransferases. The clones were isolated by selecting in vitro for protectively modified recombinants. Most of the clones modify their DNA fully but a substantial number modify only partially. In approximately one-half of the clones, the genes for the corresponding endonucleases are also present. Some of these clones restrict infecting phages and others do not. Clones carrying endonuclease genes but lacking methyltransferase genes have been found, in several instances, to be viable.
我们已将38种II型细菌修饰甲基转移酶的基因克隆到大肠杆菌中。通过体外选择保护性修饰的重组体来分离这些克隆。大多数克隆能完全修饰其DNA，但相当一部分只能部分修饰。在大约一半的克隆中，也存在相应核酸内切酶的基因。其中一些克隆能限制感染的噬菌体，而另一些则不能。在一些情况下，已发现携带核酸内切酶基因但缺乏甲基转移酶基因的克隆是可行的。
