Deformylase that catalyzes the conversion of N-formylmaleamic acid to maleamate in the aerobic nicotinate degradation pathway. H2O + N-formylmaleamate = formate + H(+) + maleamate Cofactor degradation; nicotinate degradation. Repressed by NicR in the absence of 6-hydroxynicotinate (6HNA) inducer. In presence of 6HNA, repression is alleviated. Shares some sequence similarities with the AB hydrolase superfamily.