大肠杆菌中改变脱嘌呤内切酶、内切酶II和外切核酸酶III的突变及其对体内对甲基磺酸甲酯敏感性的影响。

Mutations in Escherichia coli altering an apurinic endonuclease, endonuclease II, and exonuclease III and their effect on in vivo sensitivity to methylmethanesulfonate.

作者信息

Kirtikar D M, Cathcart G R, White J G, Ukstins I, Goldthwait D A

出版信息

Biochemistry. 1977 Dec 13;16(25):5625-31. doi: 10.1021/bi00644a037.

PMID:200266

Abstract

The levels of endonuclease II, an apurinic endonuclease, and exonuclease III in the parent strains (AB 1157) of Escherichia coli and in various mutants were determined by chromatography on DEAE-cellulose. AB 3027 and NH 5016 lacked endonuclease II and exonuclease III. BW 2001 lacked the apurinic endonuclease and exonuclease III while BW 2007, BW 9093, and BW 9059 lacked only exonuclease III. Deletion mutants BW 9101 and BW 9109 lacked all three enzymes. The latter mutants locate the genes for the two endonucleases in the region of exonuclease III (chith) of 38.2 min (White et al., 1976). All of the mutants which were sensitive to methylmethanesulfonate in vivo lacked exonuclease III, but not all mutants lacking exonuclease III were MMS sensitive. The deletion mutants and NH 5016 were the exceptions.

摘要

通过DEAE - 纤维素柱层析法测定了大肠杆菌亲本菌株（AB 1157）及各种突变体中脱嘌呤内切酶II和外切核酸酶III的水平。AB 3027和NH 5016缺乏脱嘌呤内切酶II和外切核酸酶III。BW 2001缺乏脱嘌呤内切酶和外切核酸酶III，而BW 2007、BW 9093和BW 9059仅缺乏外切核酸酶III。缺失突变体BW 9101和BW 9109缺乏所有这三种酶。后一种突变体将两种内切酶的基因定位在38.2分钟的外切核酸酶III（chith）区域（怀特等人，1976年）。所有在体内对甲基磺酸甲酯敏感的突变体都缺乏外切核酸酶III，但并非所有缺乏外切核酸酶III的突变体都对甲基磺酸甲酯敏感。缺失突变体和NH 5016是例外情况。