Molecular evidence for the ancient origin of the ribosomal protection protein that mediates tetracycline resistance in bacteria.
The ribosomal protection proteins (RPPs) mediate the resistance to tetracycline (TC) in Gram-positive and Gram-negative bacteria. The RPPs display sequence similarity to translation elongation factors, EF-G/EF-2 and EF-Tu/EF-1alpha. To determine the evolutionary origin of the RPPs, we constructed a composite phylogenetic tree of the RPPs, EF-G/EF-2 and EF-Tu/EF-1alpha. This tree includes two universal trees for the EF-G/EF-2 and EF-Tu/EF-1alpha, which form clusters corresponding to the respective two groups of proteins from three superkingdoms. The cluster of RPPs was placed at a point between the EF-G/EF-2 and EF-Tu/EF-1alpha clusters. The branch length (substitutions/site) between the node for the RPP cluster and the primary divergence of the RPPs was statistically shorter than that between the node for this cluster and the primary divergence in the EF-G/EF-2 cluster. This indicates that the RPPs derived through duplication and divergence of the ancient GTPase before the divergence of the three superkingdoms. Furthermore, this suggests the RPPs' extant function occurred before the streptomycetes that include the TC-producing strains. Therefore, the RPPs evolved independent of the presence of TCs and serve a function other than antibiotic resistance. The RPPs may provide ribosomal protection against other chemical substances in the environment.
Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime, Japan.
Takeshi
T
Kobayashi
Lisa
L
Nonaka
Fumito
F
Maruyama
Satoru
S
Suzuki
D001426:Bacterial Proteins / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D019143:Evolution, Molecular; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D020653:Peptide Elongation Factor G / Q000235:genetics; D010444:Peptide Elongation Factor Tu / Q000235:genetics; D010802:Phylogeny; D012270:Ribosomes / Q000187:drug effects; D017385:Sequence Homology; D013752:Tetracycline / Q000378:metabolism / Q000494:pharmacology
D001426:Bacterial Proteins; D020648:Peptide Elongation Factor 1; D020653:Peptide Elongation Factor G; D010444:Peptide Elongation Factor Tu; D013752:Tetracycline