A novel nitrilase superfamily amidase gene, designated azl13, was cloned from Streptomyces sp. 211726. Bioinformatic and biochemical analysis indicated that Azl13 belongs to a new subfamily in branch 13 of the nitrilase superfamily. His(6)-Azl13 was expressed in Escherichia coli BL21(DE3) and had the expected molecular mass of 31 kDa, and the enzymatic activity was best at 40 A degrees C, pH 8.0. His(6)-Azl13 had amidase, aryl acylamidase, and acyl transferase activities, and it displayed an unusually wide substrate spectrum. His(6)-Azl13 was most active on 4-guanidinobutyramide, which is probably its natural substrate, moderately active on short-chain aliphatic amides and weakly active hydrolyzing aromatic and heterocyclic amides. His(6)-Azl13 also catalyzed acyl transfer to hydroxylamine from acetamide or the herbicide propanil. The substrate spectrum differs from that of the Pseudomonas amidase RamA, probably reflecting high salinity adaptation. The broad substrate spectrum of Azl13 is potentially useful for chemical synthesis and biodegradation.