Model for the peroxisomal cofactor transport in yeast. Ant1p: peroxisomal ATP carrier 1; FA, fatty acid; Faa2p: peroxisomal acyl-CoA synthetase 2 (associated at the matrix side of the peroxisomal membrane); Fat1p: peroxisomal acyl-CoA synthetase, also known as peroxisomal fatty-acid transporter 1 (integral membrane protein); NMN(H): nicotinamide mononucleotide (reduced); Npy1p: peroxisomal NAD(H) diphosphatase 1, catalyzing the hydrolysis of NADH to AMP and NMN(H); PAP: adenosine 3′,5′-diphosphate; 4′-PP: 4′-phospho-pantetheine; Pcd1p: peroxisomal CoA diphosphatase 1, catalyzing the hydrolysis of CoA to PAP and 4′-PP; Pxa1p/Pxa2p: peroxisomal ATP-binding cassette (ABC) transporter, mediating the import of fatty acids as acyl-CoA esters; (?): proposed cofactor carrier proteins.