The use of degenerate, sensor gene-specific, oligodeoxyribonucleotide primers to amplify DNA fragments from Staphylococcus aureus

Abstract

The sensor proteins of bacterial two-component regulatory systems comprise a large family of proteins that are involved in environmental sensing and signal transduction. To study these proteins in the Gram+ pathogen, Staphylococcus aureus, two pairs of degenerate oligodeoxyribonucleotides (oligos) that corresponded to conserved sequences contained within sensor protein-encoding genes were synthesized. Using these oligo primers, DNA fragments from S. aureus were amplified by polymerase chain reaction (PCR), cloned in Escherichia coli, and sequenced. Comparison of the deduced amino acid sequences from these cloned fragments to the sequences contained in the GenBank database suggest that some of the PCR products were derived from sensor protein-encoding genes. However, several other fragments were identified that encoded peptides with up to 65% identity to transport proteins. Given the biochemical and functional properties of some of these proteins, these data suggest that sensor and transport proteins may be evolutionarily related.