Catalyzes 2 different reactions between oxygen and the acireductone 1,2-dihydroxy-3-keto-5-methylthiopentene (DHK-MTPene) depending upon the metal bound in the active site (By similarity). Fe- containing acireductone dioxygenase (Fe-ARD) produces formate and 2- keto-4-methylthiobutyrate (KMTB), the alpha-ketoacid precursor of methionine in the methionine recycle pathway (PubMed:15938715). Ni- containing acireductone dioxygenase (Ni-ARD) produces methylthiopropionate, carbon monoxide and formate, and does not lie on the methionine recycle pathway (By similarity). Also down-regulates cell migration mediated by MMP14 (PubMed:14718544). Necessary for hepatitis C virus replication in an otherwise non-permissive cell line (PubMed:11602742). {ECO:0000255|HAMAP-Rule:MF_03154, ECO:0000269|PubMed:11602742, ECO:0000269|PubMed:14718544, ECO:0000269|PubMed:15938715}. This is the function of Ensembl gene identifier ENSG00000182551 (ADI1, acireductone dioxygenase 1).