Biotin Uptake in Biotin Regulatory Mutant of Escherichia coli

A versatile Escherichia coli strain for identification of biotin transporters and for biotin quantification

Biotin is an essential cofactor of carboxylase enzymes in all kingdoms of life. The vitamin is produced by many prokaryotes, certain fungi, and plants. Animals depend on biotin uptake from their diet and in humans lack of the vitamin is associated with serious disorders. Many aspects of biotin metabolism, uptake, and intracellular transport remain to be elucidated. In order to characterize the ...

The biotin carboxylase-biotin carboxyl carrier protein complex of Escherichia coli acetyl-CoA carboxylase.

Escherichia coli acetyl-CoA carboxylase (ACC) is composed of four different protein molecules. These proteins form a large but very unstable complex. Hints of a sub-complex between the biotin carboxylase (BC) and biotin carboxyl carrier protein (BCCP) subunits have been reported in the literature, but the complex was not isolated and thus the protein stoichiometry could not be determined. We re...

Active transport of biotin in Escherichia coli K-12.

The transport of [(14)C]biotin into cells of a biotin prototroph, Escherichia coli K-12 strain Y10-1, was investigated. The vitamin taken up by the cells in this strain existed primarily in the free form. Addition of glucose enhanced the rate of uptake six- to eightfold and the steady level was reached in 2 to 3 min resulting in accumulation of biotin against a concentration gradient. The uptak...

A mutant of Escherichia coli that requires high concentrations of biotin.

A recessive mutation (bir) of E. coli, at 77 min on the standard map, destroys ability of the bacteria to take up biotin or to grow except at high concentrations of biotin. In a biotin prototroph, the bir mutation causes overproduction and excretion of biotin, and derepression of at least one biosynthetic gene (bioD). Growth of the bir mutant is inhibited by avidin or high concentrations of det...

Regulation of Escherichia coli Biotin Biosynthesis: Isolation of BirA