M. Matsuoka et al., Cloning and sequences of inducible and constitutive macrolide resistance genes in Staphylococcus aureus that correspond to an ABC transporter, FEMS MICROB, 181(1), 1999, pp. 91-100
A restriction map was made and the DNA sequence was determined for a plasmi
d, pMC38, derived from the inducible macrolide resistance plasmid pEP2104,
that showed constitutive resistance to PMS: antibiotics (partial macrolide
and streptogramin B antibiotics). A 5.04 kb SalI-PstI fragment (fragment C)
of pMC38, which encoded PMS resistance, was cloned into a shuttle vector,
pRIT5, to yield pMR504. The transformant Staphylococcus aureus 4220 (pMR504
) exhibited constitutive PMS resistance. Fragment C was subcloned to pUC19
in order to determine the DNA sequence. This sequence was consequently foun
d to contain three open reading frames (ORF1-3), of which ORF3 corresponded
to the 63 kDa membrane protein (MsrSA) that expressed PMS resistance. Acco
rding to DNA sequence comparison of the control region of ORF3 in pMC38 and
pEP2104, 44 nucleolides including RBSI and the leader peptide (MTASMRLK) w
ere deleted on plasmid pMC38, This suggests that the leader peptide is esse
ntial for the inducible expression of PMS resistance. (C) 1999 Federation o
f European Microbiological Societies. Published by Elsevier Science B.V. Al
l rights reserved.