Post-transcriptional regulation by distal Shine-Dalgarno sequences in the grpE-dnaK intergenic region of Streptococcus mutans.

ABSTRACT: A unique 373 bp region (igr66) between grpE and dnaK of Streptococcus mutans lacks a promoter but is required for optimal production of DnaK. Northern blotting using probes specific to hrcA, igr66 or dnaK revealed multiple transcripts produced from the dnaK operon and 5'-RACE mapped 5' termini of multiple dnaK transcripts within igr66. One product mapped to a predicted 5'-SL (stem-loop) and two others mapped just 5' to Shine-Dalgarno (SD)-like sequences located immediately upstream to dnaK and to a predicted SL 120 bp upstream of the dnaK start codon (3'-SL). A collection of cat reporter-gene strains containing mutant derivatives of igr66 were engineered. Chloramphenicol acetyltransferase (CAT) activity varied greatly between strains, but there were no correlative changes in cat mRNA level

SUBMITTER: Palmer SR 

PROVIDER: S-EPMC4666293 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature