The Staphylococcus aureus transposon Tn551: Complete nucleotide sequence and transcriptional analysis of the expression of the erythromycin resistance gene

The complete nucleotide sequence of Staphylococcus aureus transposon Tn551 was determined. The 5,266-bp sequence encoded five putative proteins. Compa rison of the nucleotide sequence of Tn551 with that of the enterococcal tra nsposon Tn917 showed that the two transposons were 99.8% identical and diff ered only at 11 positions along the entire sequence. The genetic organizati on of Tn551 was also identical to that of Tn917. Northern analysis of RNA p repared from a staphylococcal strain bearing Tn551 displayed three em-assoc iated transcripts that were constitutively produced. Mapping of the 5' ends of the transcripts by primer extension suggested that the constitutive tra nscription of erm was initiated from a nucleotide located 5 bp downstream o f ORF1. A second set of three erythromycin-inducible transcripts was also d etected and these showed a pattern similar to that described for Tn917, A s imple and rapid method is described for the use of the Tn551 sequence infor mation in sequencing transposon-inactivated staphylococcal genes.