biostudies-otherDuncan MJNIDCR NIH HHS3930-4https://www.ebi.ac.uk/biostudies/studies/S-EPMC258979Previously, the fructose-1,6-diphosphate-dependent L-(+)-lactate dehydrogenase gene of Streptococcus mutans JH1000 was cloned into Escherichia coli (J. D. Hillman, M. J. Duncan, and K. P. Stashenko, Infect. Immun. 58:1290-1295, 1990). In the present study, the nucleotide sequence of 1.29 kb of S. mutans DNA which contained the promoter and protein-coding region of the gene was determined. In vitro disruption of the gene was achieved by deletion of the promoter and a major portion of the protein-coding sequence. Subsequently, a tetracycline resistance gene from S. mutans was inserted at the deletion site as a marker for selection. In addition, evidence from Southern hybridization showed that S. mutans JH1000 contained a single copy of the lactate dehydrogenase gene.biostudies-otherEurope PMCUnknown59(11)Infection and immunityPMC258979DE04529Hillman JDDuncan MJfalseDNA sequence and in vitro mutagenesis of the gene encoding the fructose-1,6-diphosphate-dependent L-(+)-lactate dehydrogenase of Streptococcus mutans.Previously, the fructose-1,6-diphosphate-dependent L-(+)-lactate dehydrogenase gene of Streptococcus mutans JH1000 was cloned into Escherichia coli (J. D. Hillman, M. J. Duncan, and K. P. Stashenko, Infect. Immun. 58:1290-1295, 1990). In the present study, the nucleotide sequence of 1.29 kb of S. mutans DNA which contained the promoter and protein-coding region of the gene was determined. In vitro disruption of the gene was achieved by deletion of the promoter and a major portion of the protein-coding sequence. Subsequently, a tetracycline resistance gene from S. mutans was inserted at the deletion site as a marker for selection. In addition, evidence from Southern hybridization showed that S. mutans JH1000 contained a single copy of the lactate dehydrogenase gene.1991-01-01T00:00:00Z1991 Nov2019-03-27T00:35:57Z2019-03-27T00:35:57ZS-EPMC258979M725451937751