Key steps in normal translation termination and recycling. mRNA is shown in gray with the thicker line depicting the coding sequence and the thinner line depicting the “normal” 3′ UTR. The ribosome is shown in blue, and other termination factors are labeled. A, normal translation termination begins when eRF1 recognizes a termination codon (shown as UGA) and the following nucleotide (+4 position; preferred nucleotides are shown) in the A-site along with the GTP-bound form of eRF3 to form the termination complex. B, GTP hydrolysis by eRF3 causes a conformational change in eRF1 that positions it to mediate hydrolysis and release of the nascent polypeptide. C, eRF3-GDP dissociates from the termination complex, and ABCE1, bound to ATP, joins to begin ribosome recycling. D, ATP hydrolysis by ABCE1 leads to ribosome splitting followed by dissociation of eRF1, ABCE1, and 60S from the mRNA. E, the 40S recycling factor heterodimer MCT-1/DENR binds the terminated ribosome. F, the 40S subunit and P-site tRNA are then removed from the mRNA by MCT-1/DENR, freeing all ribosome components to engage in another round of translation.