Nucleotide sequence of Streptococcus mutans superoxide dismutase gene and isolation of insertion mutants.
A gene (sod) encoding superoxide dismutase (SOD) was cloned from Streptococcus mutans in Escherichia coli, and its nucleotide sequence was determined. The presumptive amino acid sequence of its product revealed that the SOD is basically of Mn type. Insertional inactivation of the sod gene resulted in the loss of SOD activity in crude extracts, indicating that the gene represents the only functional gene for SOD in S. mutans. Moreover, Southern blot analysis indicated that the S. mutans chromosome had no additional gene which was hybridizable with an oligonucleotide probe specific for an SOD motif. The SOD-deficient mutants were able to grow aerobically, albeit more slowly than the parent strains.
Nakayama
K
K
Department of Microbiology, Faculty of Dentistry, Kyushu University, Fukuoka, Japan.
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D013295:Streptococcus mutans / Q000201:enzymology* / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics* / Q000502:physiology
D004251:DNA Transposable Elements; D013482:Superoxide Dismutase