CHARACTERIZATION OF PEPR1, A GENE CODING FOR A POTENTIAL TRANSCRIPTIONAL REGULATOR OF LACTOBACILLUS DELBRUECKII SUBSP LACTIS DSM7290

摘要

The gene designated pepRI, encoding a potential transcription regulator of Lactobacillus delbrueckii subsp. lactis DSM7290, was identified by sequence similarity of an open reading frame located upstream of the prolidase pepQ orientated in opposite direction. pepQ and pepRI coding regions are spaced by 152 nucleotides. Upstream of the -35 region of pepQ, a 14-bp palindromic sequence, homologous to the catabolite responsive element, could be identified. The pepRI gene has the potential to encode a protein of 333 amino acids with a calculated molecular mass of 36 955 Da and a calculated pI of 5.5. The deduced protein sequence shows significant identity to the catabolite control protein of Bacillus. Co-expression in Escherichia coli was studied with the pepRI-pepQ intergenic region fused to the promoterless beta-galactosidase reporter gene. The pepQ-beta-galactosidase hybrid displayed an enhanced expression in the presence of cloned pepRI. [References: 25]