Submitted to: Plasmid Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 3, 1997
Publication Date: N/A
Interpretive Summary: The gene for resistance to the antibiotic erythromycin (EMR) is a convenient marker to track the efficiency of gene transfer and expression in dairy fermentation microorganisms (DFM) used in cheese and yogurt production. A small DNA molecule called a plasmid which is a host to the EMR gene is frequently present in microorganisms associated with farm animals. To characterize the EMR gene and its host plasmid, their building blocks called nucleic acids, and other important features were determined. The results showed that the EMR gene and its host DNA molecule had characteristics that set them apart from other genes already studied. The EMR gene is abundantly available and is convenient to use in DNA carrier development to improve the performance of industrial microorganisms used in dairy fermentations.
Technical Abstract: The 2.3-kb erythromycin resistance (EM) plasmid pPV141 of Staphylococcus chromogenes 3688 was isolated and characterized. Nucleotide sequence analysis identified ORF1 and ORF2 separated by a 445-bp spacing, encoding a 161-residue replication protein (Rep141) and a 244-residue erythromycin resistance protein (Erm, rRNA adenine N-6-methyltransferase), respectively. Structural analysis and Southern hybridization showed that the rep and ermM genes in pPV141 shared homology with the Em plasmids pPV140 (4.3kb) and pPV142 (2.4 kb) isolated from the veterinary strains S. epidermidis 6257 and S. simulans 13044, respectively, as well as other known Em plasmids. Based on sequence analysis, pPV141 was classified as a unique member of the pSN2 family of Em plasmids.