Coenzyme A (CoA) transferases belong to an evolutionary conserved family of enzymes catalyzing the reversible transfer of CoA from one carboxylic acid to another. They have been identified in many prokaryotes and in mammalian tissues. The bacterial enzymes are heterodimer of two subunits (A and B) of about 25 Kd each while eukaryotic SCOT consist of a single chain which is colinear with the two bacterial subunits.
CoA-transferases are found in organisms from all kingdoms of life. They catalyse reversible transfer reactions of coenzyme A groups from CoA-thioesters to free acids. There are at least three families of CoA-transferases, which differ in sequence and reaction mechanism:
Family I consists of CoA-transferases for 3-oxoacids ( EC 2.8.3.5EC 2.8.3.6 ), short-chain fatty acids ( EC 2.8.3.8EC 2.8.3.9 ) and glutaconate ( EC 2.8.3.12 ). Most use succinyl-CoA or acetyl-CoA as CoA donors.
Family II consists of the homodimeric alpha-subunits of citrate lyase and citramalate lyase ( EC 2.8.3.10EC 2.8.3.11 ). These enzymes catalyse the transfer of acyl carrier protein (ACP) with a covalently bound CoA derivative, but can accept free CoA thioesters as well.
Family III consists of formyl-CoA:oxalate CoA-transferase [ (PUBMED:15213226) ], succinyl-CoA:(R)-benzylsuccinate CoA-transferase [ (PUBMED:11418570) ], (E)-cinnamoyl-CoA:(R)-phenyllactate CoA-transferase [ (PUBMED:10849007) ], succinyl-CoA:mesaconate CoA-transferase [ (PUBMED:28932214) ] and butyrobetainyl-CoA:(R)-carnitine CoA-transferase [ (PUBMED:15823031) ]. These CoA-transferases occur in prokaryotes and eukaryotes, and catalyse CoA-transfer reactions in a highly substrate- and stereo-specific manner [ (PUBMED:11749953) ].
Coenzyme A (CoA) transferases belong to an evolutionary conserved [ (PUBMED:1624453) (PUBMED:9325289) ] family of enzymes catalyzing the reversible transfer of CoA from one carboxylic acid to another. They have been identified in many prokaryotes and in mammalian tissues. The bacterial enzymes are heterodimer of two subunits (A and B) of about 25 Kd each while eukaryotic SCOT consist of a single chain which is colinear with the two bacterial subunits.
This family consists of 3-oxoacid CoA-transferases and related CoA-transferases from family I.
Cloning and characterization of Helicobacter pylori succinylCoA:acetoacetate CoA-transferase, a novel prokaryotic member of theCoA-transferase family.
J Biol Chem. 1997; 272: 25659-67
Display abstract
Sequencing of a fragment of Helicobacter pylori genome led to theidentification of two open reading frames showing striking homology withCoenzyme A (CoA) transferases, enzymes catalyzing the reversible transferof CoA from one carboxylic acid to another. The genes were present in allH. pylori strains tested by polymerase chain reaction or slot blotting butnot in Campylobacter jejuni. Genes for the putative A and B subunits of H.pylori CoA-transferase were introduced into the bacterial expressionvector pKK223-3 and expressed in Escherichia coli JM105 cells. Amino acidsequence comparisons, combined with measurements of enzyme activitiesusing different CoA donors and acceptors, identified the H. pyloriCoA-transferase as a succinyl CoA:acetoacetate CoA-transferase. Thisactivity was consistently observed in different H. pylori strains.Antibodies raised against either recombinant A or B subunits recognizedtwo distinct subunits of Mr approximately 26,000 and 24, 000 that are bothnecessary for H. pylori CoA-transferase function. The lack ofalpha-ketoglutarate dehydrogenase and of succinyl CoA synthetaseactivities indicates that the generation of succinyl CoA is not mediatedby the tricarboxylic acid cycle in H. pylori. We postulate the existenceof an alternative pathway where the CoA-transferase is essential forenergy metabolism.
Characterization of the genes encoding beta-ketoadipate: succinyl-coenzymeA transferase in Pseudomonas putida.
J Bacteriol. 1992; 174: 4657-66
Display abstract
beta-Ketoadipate:succinyl-coenzyme A transferase(beta-ketoadipate:succinyl-CoA transferase) (EC 2.8.3.6) carries out thepenultimate step in the conversion of benzoate and 4-hydroxybenzoate totricarboxylic acid cycle intermediates in bacteria utilizing thebeta-ketoadipate pathway. This report describes the characterization of aDNA fragment from Pseudomonas putida that encodes this enzyme. Thefragment complemented mutants defective in the synthesis of the CoAtransferase, and two proteins of sizes appropriate to encode the twononidentical subunits of the enzyme were produced in Escherichia coli whenthe fragment was placed under the control of a phage T7 promoter. DNAsequence analysis revealed two open reading frames, designated pcaI andpcaJ, that were separated by 8 bp, suggesting that they may comprise anoperon. A comparison of the deduced amino acid sequence of the P. putidaCoA transferase genes with the sequences of two other bacterial CoAtransferases and that of succinyl-CoA:3-ketoacid CoA transferase from pigheart suggests that the homodimeric structure of the mammalian enzyme mayhave resulted from a gene fusion of the bacterial alpha and beta subunitgenes during evolution. Conserved functional groups important to thecatalytic activity of CoA transferases were also identified.
