The succinyl-CoA synthetase complex catalyzes the reversible interconversion of succinyl-CoA and succinate and releases GTP or ATP. The complex is a heterodimer composed of an invariant alpha subunit and a nucleotide-specific beta subunit. In humans, the GTP is the one mostly commonly produced. The genes are listed with aliases in parentheses, full names and links to report pages:

Suclg1 (Sucla1) – succinate-CoA ligase, alpha subunit
Suclg2 – succinate-CoA ligase, GDP forming, beta subunit
Sucla2 – succinate-CoA ligase, ADP-forming beta subunit