A paralog of lysyl-tRNA synthetase aminoacylates a conserved lysine residue in translation elongation factor P.
Aminoacyl-tRNA synthetase (aaRS) paralogs with unknown functions exist in various species. We now report novel 'protein lysylation' by an Escherichia coli lysyl-tRNA synthetase paralog, GenX/PoxA/YjeA. X-ray crystallographic analysis shows that the structure of the GenX protein resembles that of a class II aaRS. Further in vitro studies reveal that it specifically aminoacylates EF-P with lysine. The shape of the protein substrate mimics that of the L-shaped tRNA, and its lysylation site corresponds to the tRNA 3' end. Thus, we show how the aaRS architecture can be adapted to achieve aminoacylation of a specific protein. Moreover, in vivo analyses reveal that the translation elongation factor P (EF-P) lysylation by GenX is enhanced by YjeK (lysine 2,3-aminomutase paralog), which is encoded next to the EF-P gene, and might convert alpha-lysyl-EF-P to beta-lysyl-EF-P. In vivo analyses indicate that the EF-P modification by GenX and YjeK is essential for cell survival.
Yanagisawa
Tatsuo
T
RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama, Japan.
Sumida
Tomomi
T
Ishii
Ryohei
R
Takemoto
Chie
C
Yokoyama
Shigeyuki
S
D049148:Aminoacylation; D000818:Animals; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D006801:Humans; D008239:Lysine / Q000378:metabolism; D008250:Lysine-tRNA Ligase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
D010445:Peptide Elongation Factors; C020746:factor EF-P; D008250:Lysine-tRNA Ligase; D008239:Lysine