Sequencing analysis of mutation points in the biotin operon of biotin-overproducing Escherichia coli mutants.
We analyzed mutation points of the biotin operon from biotin-overproducing mutants of Escherichia coli resistant to two biotin analogs, actithiazic acid and 5-(2-thienyl)-valeric acid, by DNA sequencing. The biotin operons cloned from these mutants were classified into three groups. One point mutation, which was a GC-->AT change within the operator overlapping the -10 region of the rightward (bioB) promoter, was considered to result in disruption of operator structure and enhancement of promoter activity. Two other point mutations, which were both GC-->AT changes just before and after the initiation codon of the bioB gene, were considered to activate the translation efficiency. These mutations significantly accelerated the biotin-forming activity from dethiobiotin in cell-free extracts.
Ifuku
O
O
Shiseido Research Center, Yokohama, Japan.
Haze
S
S
Kishimoto
J
J
Koga
N
N
Yanagi
M
M
Fukushima
S
S
D001483:Base Sequence; D001710:Biotin / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D002208:Caproates / Q000494:pharmacology; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009876:Operon; D010421:Pentanoic Acids / Q000494:pharmacology; D017354:Point Mutation; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines
D002208:Caproates; D004269:DNA, Bacterial; D010421:Pentanoic Acids; D013844:Thiazoles; D053778:Thiazolidines; C015538:5-(2-thienyl)valeric acid; D001710:Biotin; C010250:mycobacidin