Abstract
The effect of the upstream region of the β-lactamase structural gene was studied on the production of β-lactamase from Streptomyces fradiae Y59. In contrast to the case in S. cacaoi, β-lactamase activity was weakly enhanced by the presence of the upstream 5-kb DNA fragment but was not induced by 7-ACA. The sequence analysis of this region revealed a couple of putative regulatory proteins, although their actual functions were not clear. It was therefore suggested that at least one of the ORFs might be involved in the weak enhancement of β-lactamase gene expression of S. fradiae Y59
