title: Cloning, sequence, and expression of the L-(+) lactate dehydrogenase of Streptococcus bovis.
abstract: The ldh gene encoding the fructose-1,6-diphosphate-dependent L-(+) lactate dehydrogenase from the ruminal bacterium Streptococcus bovis was cloned and sequenced. A genomic library of S. bovis JB1 DNA was constructed in lambda ZAP II and screened by use of a heterologous probe derived from the cloned Streptococcus mutans ldh gene. Several clones were isolated that contained a common 2.9-kb fragment as determined by restriction analysis. Nucleotide sequence analysis revealed a 987-bp open reading frame with extensive homology to Streptococcus thermophilus and S. mutans ldh nucleic acid and amino acid sequences. Expression of the cloned S. bovis ldh gene in Escherichia coli was confirmed by the ability to complement the ldh mutation of E. coli FMJ39, by using an in-gel activity screen and by enzymatic assay. Increased LDH activity was observed in S. bovis JB1 containing the cloned ldh genes on a multicopy plasmid.
authors.affiliation: Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, U.S. Department of Agriculture, Agricultural Research Service, Peoria, IL 61604, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Wyckoff
authors.forename: J
authors.initials: J
authors.lastname: Chow
authors.forename: T R
authors.initials: TR
authors.lastname: Whitehead
authors.forename: M A
authors.initials: MA
authors.lastname: Cotta
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D015698:Genomic Library; D007770:L-Lactate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D012417:Rumen / Q000382:microbiology; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D016985:Streptococcus bovis / Q000201:enzymology / Q000235:genetics*
chemical_list: D011994:Recombinant Proteins; D007770:L-Lactate Dehydrogenase