4wf2: Difference between revisions
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== Function == | == Function == | ||
[[http://www.uniprot.org/uniprot/BIRA_ECOLI BIRA_ECOLI]] Acts both as a biotin--[acetyl-CoA-carboxylase] ligase and a biotin-operon repressor. In the presence of ATP, BirA activates biotin to form the BirA-biotinyl-5'-adenylate (BirA-bio-5'-AMP or holoBirA) complex. HoloBirA can either transfer the biotinyl moiety to the biotin carboxyl carrier protein (BCCP) subunit of acetyl-CoA carboxylase, or bind to the biotin operator site and inhibit transcription of the operon.<ref>PMID:6129246</ref> <ref>PMID:2667763</ref> <ref>PMID:8003500</ref> <ref>PMID:12527300</ref> | [[http://www.uniprot.org/uniprot/BIRA_ECOLI BIRA_ECOLI]] Acts both as a biotin--[acetyl-CoA-carboxylase] ligase and a biotin-operon repressor. In the presence of ATP, BirA activates biotin to form the BirA-biotinyl-5'-adenylate (BirA-bio-5'-AMP or holoBirA) complex. HoloBirA can either transfer the biotinyl moiety to the biotin carboxyl carrier protein (BCCP) subunit of acetyl-CoA carboxylase, or bind to the biotin operator site and inhibit transcription of the operon.<ref>PMID:6129246</ref> <ref>PMID:2667763</ref> <ref>PMID:8003500</ref> <ref>PMID:12527300</ref> | ||
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== Publication Abstract from PubMed == | |||
Intrinsic disorder provides a means of maximizing allosteric coupling in proteins. However, the mechanisms by which the disorder functions in allostery remain to be elucidated. Small ligand, bio-5'-AMP, binding and dimerization of the Escherichiacoli biotin repressor are allosterically coupled. Folding of a disordered loop in the allosteric effector binding site is required to realize the full coupling free energy of -4.0+/-0.3kcal/mol observed in the wild-type protein. Alanine substitution of a glycine residue on the dimerization surface that does not directly contribute to the dimerization interface completely abolishes this coupling. In this work, the structure of this variant, solved by X-ray crystallography, reveals a monomeric corepressor-bound protein. In the structure loops, neither of which contains the alanine substitution, on both the dimerization and effector binding surfaces that are folded in the corepressor-bound wild-type protein are disordered. The structural data combined with functional measurements indicate that allosteric coupling between ligand binding and dimerization in BirA (E. coli biotin repressor/biotin protein ligase) is achieved via reciprocal communication of disorder-to-order transitions on two distant functional surfaces. | |||
Allosteric Coupling via Distant Disorder-to-Order Transitions.,Eginton C, Cressman WJ, Bachas S, Wade H, Beckett D J Mol Biol. 2015 Mar 4. pii: S0022-2836(15)00155-2. doi:, 10.1016/j.jmb.2015.02.021. PMID:25746672<ref>PMID:25746672</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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== References == | == References == | ||
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