The Transcriptional Regulation Of Camp Receptor Protein (CRP) On AllS In Klebsiella Pneumonia

Objective To investigate the transcriptional regulation mechanism of cAMP receptor protein(CRP) on gene allS in Klebsiella pneumonia.Methods The putative promoter regions of allS were amplified from K2044 and subcloned into placZ15 to fuse the lacZ reporter. The reporter plasmids placZ15-p1357 was introduced into the WT CCW01 and the deletion mutant CCW01:△crp. To verify the regulation of CRP on allS by measuring the β-galactosidase activity. The RT-PCR was carried out to verify the WT and △ crp. With the entire promoter region of allS gene was amplified from WT strain and the CRP protein was expressed and purified. Then, the electrophoretic mobility shift assay was used to study the regulation of CRP on allS. And DNase I footprinting experiment was used to confirm the specific binding sites of CRP on allS.Results The lacZ fusion experiment, RT-PCR, electrophoretic mobility shift and DNase I footprinting assays revealed that CRP could bind to the allS promoter-proximal region and the binding site was further refined to be located from 60 bp to 94 bp upstream of the allS promoter.Conclusions The transcription of gene allS is positively regulated by CRP via directly binding to upstream of all S promoter. The study supplements the regulatory network of CRP and knows the regulation mechanism of the pathogen better.