InterPro : IPR016143

Name  Citrate synthase-like, small alpha subdomain Short Name  Citrate_synth-like_sm_a-sub
Type  Domain Description  Citrate synthase is a member of a small family of enzymes that can directly form a carbon-carbon bond without the presence of metal ion cofactors. It catalyses the first reaction in the Krebs' cycle, namely the conversion of oxaloacetate and acetyl-coenzyme A into citrate and coenzyme A. This reaction is important for energy generation and for carbon assimilation. The reaction proceeds via a non-covalently bound citryl-coenzyme A intermediate in a 2-step process (aldol-Claisen condensation followed by the hydrolysis of citryl-CoA). Citrate synthase enzymes are found in two distinct structural types: type I enzymes (found in eukaryotes, Gram-positive bacteria and archaea) form homodimers and have shorter sequences than type II enzymes, which are found in Gram-negative bacteria and are hexameric in structure. In both types, the monomer is composed of two domains: a large alpha-helical domain consisting of two structural repeats, where the second repeat is interrupted by a small alpha-helical domain. The cleft between these domains forms the active site, where both citrate and acetyl-coenzyme A bind. The enzyme undergoes a conformational change upon binding of the oxaloacetate ligand, whereby the active site cleft closes over in order to form the acetyl-CoA binding site []. The energy required for domain closure comes from the interaction of the enzyme with the substrate. Type II enzymes possess an extra N-terminal beta-sheet domain, and some type II enzymes are allosterically inhibited by NADH [].This entry represents the small alpha-helical domain from type I and II citrate synthase enzymes, as well as a homolgous domain found in the related enzyme ATP citrate synthase. ATP citrate synthase () (also known as ATP citrate lyase) catalyses the MgATP-dependent, CoA-dependent cleavage of citrate into oxaloacetate and acetyl-CoA, a key step in the reductive tricarboxylic acid pathway of CO2 assimilation used by a variety of autotrophic bacteria and archaea to fix carbon dioxide []. ATP citrate synthase is composed of two distinct subunits. In eukaryotes, ATP citrate synthase is a homotetramer of a single large polypeptide, and is used to produce cytosolic acetyl-CoA from mitochondrial-produced citrate [].
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Sequence Features

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Proteins

InterPro protein domain ID --> Contigs

 

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3 Found In

Id Name Short Name Type
IPR002020 Citrate synthase-like Citrate_synthase-like Family
IPR016141 Citrate synthase-like, core Citrate_synthase-like_core Domain
IPR014608 ATP-citrate synthase ATP-citrate_synthase Family

0 Parent Features

4 Publications

First Author Title Year Journal Volume Pages
Daidone I Investigating the accessibility of the closed domain conformation of citrate synthase using essential dynamics sampling. 2004 J Mol Biol 339 515-25
Francois JA Structure of a NADH-insensitive hexameric citrate synthase that resists acid inactivation. 2006 Biochemistry 45 13487-99
Kim W Both subunits of ATP-citrate lyase from Chlorobium tepidum contribute to catalytic activity. 2006 J Bacteriol 188 6544-52
Bauer DE ATP citrate lyase is an important component of cell growth and transformation. 2005 Oncogene 24 6314-22



To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)