EC 2.8.3.18     
Accepted name: succinyl-CoA:acetate CoA-transferase
Reaction: succinyl-CoA + acetate = acetyl-CoA + succinate
Other name(s): aarC (gene name); SCACT
Systematic name: succinyl-CoA:acetate CoA-transferase
Comments: In some bacteria the enzyme catalyses the conversion of acetate to acetyl-CoA as part of a modified tricarboxylic acid (TCA) cycle [3,5,6]. In other organisms it converts acetyl-CoA to acetate during fermentation [1,2,4,7]. In some organisms the enzyme also catalyses the activity of EC 2.8.3.27, propanoyl-CoA:succinate CoA transferase.
References:
1.  Steinbuchel, A. and Muller, M. Anaerobic pyruvate metabolism of Tritrichomonas foetus and Trichomonas vaginalis hydrogenosomes. Mol. Biochem. Parasitol. 20 (1986) 57–65. [PMID: 3090435]
2.  Sohling, B. and Gottschalk, G. Molecular analysis of the anaerobic succinate degradation pathway in Clostridium kluyveri. J. Bacteriol. 178 (1996) 871–880. [PMID: 8550525]
3.  Mullins, E.A., Francois, J.A. and Kappock, T.J. A specialized citric acid cycle requiring succinyl-coenzyme A (CoA):acetate CoA-transferase (AarC) confers acetic acid resistance on the acidophile Acetobacter aceti. J. Bacteriol. 190 (2008) 4933–4940. [PMID: 18502856]
4.  van Grinsven, K.W., van Hellemond, J.J. and Tielens, A.G. Acetate:succinate CoA-transferase in the anaerobic mitochondria of Fasciola hepatica. Mol. Biochem. Parasitol. 164 (2009) 74–79. [PMID: 19103231]
5.  Mullins, E.A. and Kappock, T.J. Crystal structures of Acetobacter aceti succinyl-coenzyme A (CoA):acetate CoA-transferase reveal specificity determinants and illustrate the mechanism used by class I CoA-transferases. Biochemistry 51 (2012) 8422–8434. [PMID: 23030530]
6.  Kwong, W.K., Zheng, H. and Moran, N.A. Convergent evolution of a modified, acetate-driven TCA cycle in bacteria. Nat Microbiol 2:17067 (2017). [PMID: 28452983]
7.  Zhang, B., Lingga, C., Bowman, C. and Hackmann, T.J. A new pathway for forming acetate and synthesizing ATP during fermentation in bacteria. Appl. Environ. Microbiol. 87 (2021) e0295920. [PMID: 33931420]
[EC 2.8.3.18 created 2013, modified 2022]