1dv2
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The structure of biotin carboxylase, mutant E288K, complexed with ATP
OverviewOverview
Acetyl-CoA carboxylase catalyzes the first committed step in fatty acid, synthesis. In Escherichia coli, the enzyme is composed of three distinct, protein components: biotin carboxylase, biotin carboxyl carrier protein, and carboxyltransferase. The biotin carboxylase component has served for, many years as a paradigm for mechanistic studies devoted toward, understanding more complicated biotin-dependent carboxylases. The, three-dimensional x-ray structure of an unliganded form of E. coli biotin, carboxylase was originally solved in 1994 to 2.4-A resolution. This study, revealed the architecture of the enzyme and demonstrated that the protein, belongs to the ATP-grasp superfamily. Here we describe the, three-dimensional structure of the E. coli biotin carboxylase complexed, with ATP and determined to 2.5-A resolution. The major conformational, change that occurs upon nucleotide binding is a rotation of approximately, 45(o) of one domain relative to the other domains thereby closing off the, active site pocket. Key residues involved in binding the nucleotide to the, protein include Lys-116, His-236, and Glu-201. The backbone amide groups, of Gly-165 and Gly-166 participate in hydrogen bonding interactions with, the phosphoryl oxygens of the nucleotide. A comparison of this closed form, of biotin carboxylase with carbamoyl-phosphate synthetase is presented.
About this StructureAbout this Structure
1DV2 is a Single protein structure of sequence from Escherichia coli with ATP as ligand. Active as Biotin carboxylase, with EC number 6.3.4.14 Full crystallographic information is available from OCA.
ReferenceReference
Movement of the biotin carboxylase B-domain as a result of ATP binding., Thoden JB, Blanchard CZ, Holden HM, Waldrop GL, J Biol Chem. 2000 May 26;275(21):16183-90. PMID:10821865
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