Catalyzes the ferredoxin-dependent oxidative decarboxylation of pyruvate. Required for the transfer of electrons from pyruvate to ferredoxin (PubMed:9294422, PubMed:7612653). Ferredoxin I and ferredoxin II, which are single 4Fe-4S cluster ferredoxins are the most effective electron carriers of POR (PubMed:7612653). CoA + 2 oxidized [2Fe-2S]-[ferredoxin] + pyruvate = acetyl-CoA + CO2 + H(+) + 2 reduced [2Fe-2S]-[ferredoxin] Binds 3 [4Fe-4S] clusters per subunit. Binds 1 thiamine pyrophosphate per subunit. Binds 1 Mg(2+) ion per subunit. Homodimer. Belongs to the pyruvate:ferredoxin/flavodoxin oxidoreductase family.