Open AccessIdentification of sbcD mutations as cosuppressors of recBC that allow propagation of DNA palindromes in Escherichia coli K-12
Author(s) -
Fernando Gibson,
David R. F. Leach,
Robert G. Lloyd
Publication year - 1992
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.174.4.1222-1228.1992
Subject(s) - biology , genetics , recbcd , lambda phage , palindromic sequence , gene , escherichia coli , open reading frame , mutation , palindrome , microbiology and biotechnology , bacteriophage , peptide sequence , crispr
The function of an open reading frame (orf-45) located upstream of the sbcC gene of Escherichia coli was investigated. Mutations that inactivate sbcC improve the ability to propagate lambda red gam phage that carry a palindromic sequence in their DNA. They also act with sbcB mutations as cosuppressors of the defects in recombination, DNA repair, and cell viability associated with recBC mutations. A 1,282-bp cassette encoding resistance to kanamycin was used to disrupt orf-45. The mutation, which has a polar effect on the expression of sbcC, allowed stable propagation of palindromic lambda phage even when the sbcC gene product was provided in trans. Additional nonpolar mutations in orf-45 were isolated on the basis of their ability to improve the growth of recBC sbcB strains. These mutations also confer resistance to mitomycin C, allow efficient recombination in Hfr crosses, and facilitate stable propagation of palindromic phage. It is concluded that the products of orf-45 and sbcC are functionally related. The orf-45 gene is therefore renamed sbcD.