New lnu(C) gene conferring resistance to lincomycin by nucleotidylation in Streptococcus agalactiae UCN36.
Streptococcus agalactiae UCN36 was resistant to lincomycin (MIC = 16 microg/ml) but susceptible to clindamycin (MIC = 0.12 microg/ml) and erythromycin (MIC = 0.06 microg/ml). A 4-kb HindIII fragment was cloned from S. agalactiae UCN36 total DNA on plasmid pUC18 and introduced into Escherichia coli AG100A, where it conferred resistance to lincomycin. The sequence analysis of the fragment showed the presence of a 1,724-bp element delineated by imperfect inverted repeats (22 of 25 bp) and inserted in the operon for capsular synthesis of S. agalactiae UCN36. This element carried two open reading frames (ORF). The deduced amino acid sequence of the upstream ORF displayed similarity with transposases from anaerobes and IS1. The downstream ORF, lnu(C), encoded a 164-amino-acid protein with 26% to 27% identity with the LnuA(N2), LnuA, and LnuA' lincosamide nucleotidyltransferases reported for Bacteroides and Staphylococcus, respectively. Crude lysates of E. coli AG100A containing the cloned lnu(C) gene inactivated lincomycin and clindamycin in the presence of ATP and MgCl2. Mass spectrometry experiments demonstrated that the LnuC enzyme catalyzed adenylylation of lincomycin.
Service de Microbiologie and EA 2128 Relations hôte et microorganismes des épithéliums, Hôpital Côte de Nacre, Université de Caen, France.
Adeline
A
Achard
Corinne
C
Villers
Vianney
V
Pichereau
Roland
R
Leclercq
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002981:Clindamycin / Q000494:pharmacology; D003001:Cloning, Molecular; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D006801:Humans; D008034:Lincomycin / Q000378:metabolism / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C502938:lnu(C) protein, Streptococcus agalactiae; D002981:Clindamycin; D008034:Lincomycin; D009713:Nucleotidyltransferases