Enables GDP binding activity; succinate-CoA ligase (ADP-forming) activity; and succinate-CoA ligase (GDP-forming) activity. Involved in succinate metabolic process; succinyl-CoA metabolic process; and tricarboxylic acid cycle. Located in mitochondrion. Part of succinate-CoA ligase complex (GDP-forming). Human ortholog(s) of this gene implicated in mitochondrial DNA depletion syndrome 9. Orthologous to human SUCLG1 (succinate-CoA ligase GDP/ADP-forming subunit alpha). [provided by Alliance of Genome Resources, Apr 2022]