Biotin sensing at the molecular level.
Biotin influences transcription in organisms from bacteria to humans. The enzyme, biotin protein ligase, which catalyzes post-transcriptional biotin addition to biotin-dependent carboxylases, plays a central roll in transmitting the demand for biotin to gene expression. The molecular mechanism of this communication in bacteria is well understood and involves competing protein:protein interactions. Biochemical measurements indicate that this competition is kinetically controlled. In humans, the biochemistry of biotin sensing at the transcriptional level is not well characterized. However, the biotin holoenzyme ligase (holocarboxylase synthetase) is proposed to both catalyze biotin addition to carboxylases and to histones in its metabolic and transcriptional roles, respectively. Control of human holocarboxylase synthetase function is, however, considerably more complex than the simple competitive protein protein interactions observed in bacterial systems.
Beckett
Dorothy
D
Department of Chemistry and Biochemistry, College of Chemical and Life Sciences, University of Maryland, College Park, MD 20742, USA. dbeckett@umd.edu
D001692:Biological Transport; D001710:Biotin / Q000378:metabolism*; D019731:Carbon-Nitrogen Ligases / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans
D001710:Biotin; D019731:Carbon-Nitrogen Ligases; C023312:holocarboxylase synthetases