TY - JOUR
T1 - Antibiotic resistance evolved via inactivation of a ribosomal RNA methylating enzyme
AU - Stojković, Vanja
AU - Noda-Garcia, Lianet
AU - Tawfik, Dan S.
AU - Fujimori, Danica Galonić
AU - Stojkovic, Vanja
AU - Fujimori, Danica Galonic
N1 - Publisher Copyright: © 2016 The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.
PY - 2016/10/14
Y1 - 2016/10/14
N2 - Modifications of the bacterial ribosome regulate the function of the ribosome and modulate its susceptibility to antibiotics. By modifying a highly conserved adenosine A2503 in 23S rRNA, methylating enzyme Cfr confers resistance to a range of ribosome-targeting antibiotics. The same adenosine is also methylated by RlmN, an enzyme widely distributed among bacteria. While RlmN modifies C2, Cfr modifies the C8 position of A2503. Shared nucleotide substrate and phylogenetic relationship between RlmN and Cfr prompted us to investigate evolutionary origin of antibiotic resistance in this enzyme family. Using directed evolution of RlmN under antibiotic selection, we obtained RlmN variants that mediate low-level resistance. Surprisingly, these variants confer resistance not through the Cfr-like C8 methylation, but via inhibition of the endogenous RlmN C2 methylation of A2503. Detection of RlmN inactivating mutations in clinical resistance isolates suggests that the mechanism used by the in vitro evolved variants is also relevant in a clinical setting. Additionally, as indicated by a phylogenetic analysis, it appears that Cfr did not diverge from the RlmN family but from another distinct family of predicted radical SAM methylating enzymes whose function remains unknown.
AB - Modifications of the bacterial ribosome regulate the function of the ribosome and modulate its susceptibility to antibiotics. By modifying a highly conserved adenosine A2503 in 23S rRNA, methylating enzyme Cfr confers resistance to a range of ribosome-targeting antibiotics. The same adenosine is also methylated by RlmN, an enzyme widely distributed among bacteria. While RlmN modifies C2, Cfr modifies the C8 position of A2503. Shared nucleotide substrate and phylogenetic relationship between RlmN and Cfr prompted us to investigate evolutionary origin of antibiotic resistance in this enzyme family. Using directed evolution of RlmN under antibiotic selection, we obtained RlmN variants that mediate low-level resistance. Surprisingly, these variants confer resistance not through the Cfr-like C8 methylation, but via inhibition of the endogenous RlmN C2 methylation of A2503. Detection of RlmN inactivating mutations in clinical resistance isolates suggests that the mechanism used by the in vitro evolved variants is also relevant in a clinical setting. Additionally, as indicated by a phylogenetic analysis, it appears that Cfr did not diverge from the RlmN family but from another distinct family of predicted radical SAM methylating enzymes whose function remains unknown.
UR - http://www.scopus.com/inward/record.url?scp=84992316392&partnerID=8YFLogxK
U2 - https://doi.org/10.1093/nar/gkw699
DO - https://doi.org/10.1093/nar/gkw699
M3 - مقالة
C2 - 27496281
SN - 0305-1048
VL - 44
SP - 8897
EP - 8907
JO - Nucleic acids research
JF - Nucleic acids research
IS - 18
ER -