<p> 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:</p><ul><li>Family I consists of CoA-transferases for 3-oxoacids (<db_xref db="EC" dbkey="2.8.3.5"/>, <db_xref db="EC" dbkey="2.8.3.6"/>), short-chain fatty acids (<db_xref db="EC" dbkey="2.8.3.8"/>, <db_xref db="EC" dbkey="2.8.3.9"/>) and glutaconate (<db_xref db="EC" dbkey="2.8.3.12"/>). Most use succinyl-CoA or acetyl-CoA as CoA donors.</li><li>Family II consists of the homodimeric alpha-subunits of citrate lyase and citramalate lyase (<db_xref db="EC" dbkey="2.8.3.10"/>, <db_xref db="EC" dbkey="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.</li><li>Family III consists of formyl-CoA:oxalate CoA-transferase [<cite idref="PUB00031320"/>], succinyl-CoA:(R)-benzylsuccinate CoA-transferase [<cite idref="PUB00035619"/>], (E)-cinnamoyl-CoA:(R)-phenyllactate CoA-transferase [<cite idref="PUB00035620"/>], and butyrobetainyl-CoA:(R)-carnitine CoA-transferase [<cite idref="PUB00032440"/>]. These CoA-transferases occur in prokaryotes and eukaryotes, and catalyse CoA-transfer reactions in a highly substrate- and stereo-specific manner [<cite idref="PUB00019325"/>].</li></ul><p>Family III CoA-transferase family member formyl-CoA transferase transfers coenzyme A from formyl-CoA to oxalate. It forms a pathway, together with oxalyl-CoA decarboxylase, for oxalate degradation; decarboxylation by the latter gene regenerates formyl-CoA. The two enzymes typically are encoded by a two-gene operon [<cite idref="PUB00042988"/>].</p>