A Corynebacterium glutamicum rnhA recG double mutant showing lysozymesensitivity, temperature-sensitive growth, and UV-sensitivity

作者：Hirasawa T; Kumagai Y; Nagai K; Wachi M^*

来源：Bioscience Biotechnology and Biochemistry, 2003, 67(11): 2416-2424.

DOI：10.1271/bbb.67.2416

• Corynebacterium glutamicum
• lysozyme-sensitive mutant
• rnhA
• recG

Corynebacterium glutamicum mutant KY9707 was originally isolated for lysozyme-sensitivity, and showed temperature-sensitive growth. Two DNA fragments from a wild-type C. glutamicum chromosomal library suppressed the temperature-sensitivity of KY9707. These clones also rescued the lysozyme-sensitivity of KY9707, although partially. One of them encodes a protein of 382 amino acid residues, the N-terminal domain of which was homologous to RNase HI. This gene suppressed the temperature-sensitive growth of an Escherichia coli rnhA rnhB double mutant. We concluded that this gene encodes a functional RNase HI of C. glutamicum and designated it as rnhA. The other gene encodes a protein of 707 amino acid residues highly homologous to RecG protein. The C glutamicum recG gene complemented the UV-sensitivity of E. coli recG258::kan mutant. KY9707 showed increased UV-sensitivity, which was partially rescued by either the recG or rnhA gene of C. gluamicum. Point mutations were found in both recG and rnhA genes in KY9707. These suggest that temperature-sensitive growth, UV-sensitivity, and probably lysozyme-sensitivity also, of KY9707 were caused by mutations in the genes encoding RNase HI and RecG.

• 出版日期2003-11