限制性内切酶RsrI（EcoRI的同裂酶）的纯化与特性分析

Purification and characterization of the restriction endonuclease RsrI, an isoschizomer of EcoRI.

作者信息

Greene P J, Ballard B T, Stephenson F, Kohr W J, Rodriguez H, Rosenberg J M, Boyer H W

机构信息

Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0554.

出版信息

Gene. 1988 Aug 15;68(1):43-51. doi: 10.1016/0378-1119(88)90597-5.

DOI:10.1016/0378-1119(88)90597-5

PMID:2851493

Abstract

Rhodobacter sphaeroides strain 630 produces restriction enzyme RsrI which is an isoschizomer of EcoRI. We have purified this enzyme and initiated a comparison with the EcoRI endonuclease. The properties of RsrI are consistent with a reaction mechanism similar to that of EcoRI: the position of cleavage within the -GAATTC-site is identical, the MgCl2 optimum for the cleavage is identical, and the pH profile is similar. Methylation of the substrate sequence by the EcoRI methylase protects the site from cleavage by the RsrI endonuclease. RsrI cross-reacts strongly with anti-EcoRI serum indicating three-dimensional structural similarities. We have determined the sequence of 34 N terminal amino acids for RsrI and this sequence possesses significant similarity to the EcoRI N terminus.

摘要

球形红杆菌630菌株产生限制性内切酶RsrI，它是EcoRI的同裂酶。我们已纯化该酶，并开始与EcoRI内切核酸酶进行比较。RsrI的特性与类似于EcoRI的反应机制一致：在-GAATTC-位点内的切割位置相同，切割的最佳MgCl2相同，并且pH曲线相似。EcoRI甲基化酶对底物序列的甲基化保护该位点不被RsrI内切核酸酶切割。RsrI与抗EcoRI血清强烈交叉反应，表明三维结构相似。我们已确定RsrI的34个N端氨基酸序列，该序列与EcoRI的N端具有显著相似性。