Very little information is currently available concerning the pathogenic determinants produced by Alternaria brassicae, the causal agent of the blackspot disease of crucifers. We screened a genomic library of this fungus and identified a nonribosomal peptide synthetase (NRPS) gene named AbrePsy1. The complete coding sequence is 22 kbp long and encodes a large protein (792 kDa) showing typical NRPS modular organization. Structural analysis of AbrePsy1 revealed four complete elongation modules, two of which have epimerization domains. In the vicinity of AbrePsy1, a second gene (named AbreAtr1), which encodes an ATP-binding cassette transporter was identified. Increased expression of AbrePsy1 and AbreAtr1 was observed during host-plant infection. However, while physically linked, these two genes are probably not functionally clustered, as their expression patterns differed.