Regulation and function of ammonia-assimilating enzymes in Streptococcus mutans.
AUTOR(ES)
St Martin, E J
RESUMO
The ability of Streptococcus mutans to synthesize amino acids was examined. A total of 8 of 12 laboratory strains grew anaerobically on solid-defined medium that contained no amino acids. Several isolates, therefore, assimilated ammonia for the biosynthesis of amino acids. These strains included representatives of five serotypes. One strain, DR0001, was also grown in liquid-defined medium. The enzymes of two pathways by which ammonia can be fixed were detected in this strain DR0001 could use either a reduced nicotinamide adenine dinucleotide phosphate-coupled glutamate dehydrogenase or the combined action of adenosine 5'-triphosphate-driven glutamine synthetase with a reduced nicotinamide adenine dinucleotide-coupled glutamate synthase to assimilate ammonia for the biosynthesis of amino acids. Evidence that both pathways were functional was provided by an analysis of the influence of the nitrogen source on enzyme levels and by the isolation and characterization of glutamate dehydrogenase-negative mutants.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=550915Documentos Relacionados
- Regulation and function of sucrose 6-phosphate hydrolase in Streptococcus mutans.
- Genetic regulation of fructosyltransferase in Streptococcus mutans.
- Regulation of hexitol catabolism in Streptococcus mutans.
- Antigenic relatedness of glucosyltransferase enzymes from streptococcus mutans.
- Biological function of the dTDP-rhamnose synthesis pathway in Streptococcus mutans.
