Promoters P3 , Pa / Pb , P4 , and P5 Upstream from bla TEM Genes and Their Relationship to β-Lactam Resistance

Abstract
Using an isogenic system, we have determined the impact that the four promoters known to control bla TEM gene expression have on β-lactamase activity. For both TEM-1 and TEM-30, this activity gradually increased in relation to the presence of promoters P3 , Pa/Pb , and P4 upstream of the corresponding gene. Promoter P5 , only found upstream of the bla TEM-1B gene, was related to the highest expression of this gene.