Deletion and mutational analysis of the promoter P-dapA from Corynebacterium glutamicum was performed to identify regions and particular nucleotides important for its function. An extended -10 region and a stretch of six T's at positions -55 to -50 were found to be the most important elements in the promoter function. The results of mutational analysis of P-dapA are consistent with the conclusions of statistical computer-aided analysis of 44 C. glutamicum promoter sequences.