Fig 5. The tRNA^Glu mcm⁵s² modification is present in Toxoplasma.

(A) Depiction of where the γ-toxin endonuclease cleaves the mcm⁵s²U tRNA modification. Scissors represent cleavage site. (B) Sequence of the human (Hs-tRNA^Glu) and Toxoplasma glutamic acid tRNAs (Tg-tRNA^Glu); underlined and italicized sequences were used for Northern blot probe design. Predicted Hs-tRNA^Glu and Tg-tRNA^Glu structures generated by tRNAscan-SE [35,36]. (C) Northern blot of 5 μg total RNA isolated from intracellular and extracellular parental, TgElp3^OE, and rSAM(C284A/C287A)^OE parasites, as well as uninfected human foreskin fibroblast cells (HFF), incubated with or without the γ-toxin endonuclease for 10 min at 30°C. GluTTC and SerCGA probes specific to T. gondii and H. sapiens were used. The probe used for each blot is listed on the left along with an image representative of intact or cleaved tRNA.