Organization and transcription of a putative gene cluster encoding ribosomal protein S14 and an oligopeptide permease-like protein in the cyanobacterium Synechococcus sp. strain PCC 6301.

A 2.0-kbp Pst I DNA fragment of the unicellular cyanobacterium Synechococcus sp. strain PCC 6301 genome contains two open reading frames (ORFs). The first ORF of 100 codons potentially encodes a polypeptide having 47% amino acid identity to Escherichia coli ribosomal protein S14, suggesting it as a ribosomal protein S14 gene (rps14). The second ORF of 351 codons is located 81 bp downstream of rps14 and its deduced amino acid sequence is in part similar to that of the Salmonella typhimurium oligopeptide permease membrane protein OppC. Northern blot analysis showed that rps14 is expressed as a 0.48-kb transcript whereas no transcript was detected from ORF351. Pulsed-field electrophoresis and blot hybridization analysis revealed that rps14 is a single-copy gene and is found within a 165-kbp region located upstream of rrnA on the circular genome.