Characterization and transcription of the genes encoding enzymes involved in butyrate production in Butyrivibrio fibrisolvens.
Genes encoding enzymes that catalyze butyryl-CoA formation from acetyl-CoA in a type II strain of Butyrivibrio fibrisolvens were analyzed. The genes encoding thiolase, beta-hydroxybutyryl-CoA dehydrogenase, butyryl-CoA dehydrogenase, and electron transfer flavoproteins were clustered, but the crotonase gene was not present in this region. The deduced amino acid sequences of these enzymes were similar to those of clostridia. The clustered genes were shown to be cotranscribed. The rate of butyrate production increased with an increase in acetate concentration in the medium up to 5 mM, suggesting that the butyryl-CoA/acetate CoA transferase reaction limits butyrate production. Transcription of the clustered genes was not affected by acetate concentration, suggesting that acetate does not affect the synthesis of enzymes involved in butyryl-CoA formation. These results confirm that acetate stimulates butyrate production by acting as a CoA acceptor in the butyryl-CoA/acetate CoA transferase reaction.
Asanuma
Narito
N
Department of Life Science, College of Agriculture, Meiji University, Higashimita, Tama-ku, Kawasaki 214-8571, Japan.
Kawato
Masaru
M
Ohkawara
Sou
S
Hino
Tsuneo
T
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000235:genetics; D000085:Acetates / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000378:metabolism; D000101:Acetyl-CoA C-Acetyltransferase / Q000235:genetics; D000214:Acyl Coenzyme A / Q000096:biosynthesis / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002087:Butyrates / Q000378:metabolism*; D045856:Butyrivibrio / Q000201:enzymology* / Q000235:genetics*; D044926:Butyryl-CoA Dehydrogenase / Q000235:genetics; D004746:Enoyl-CoA Hydratase / Q000235:genetics; D005420:Flavoproteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009876:Operon; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
D000085:Acetates; D000214:Acyl Coenzyme A; D001426:Bacterial Proteins; D002087:Butyrates; D005420:Flavoproteins; C024343:butyryl-coenzyme A; D000105:Acetyl Coenzyme A; D015094:3-Hydroxyacyl CoA Dehydrogenases; C021388:3-hydroxybutyryl-CoA dehydrogenase; D044926:Butyryl-CoA Dehydrogenase; D000101:Acetyl-CoA C-Acetyltransferase; D004746:Enoyl-CoA Hydratase