Missing steps of mitochondrial translation initiation identified in plants

Translation initiation, the first step of the translation cycle, involves initiation factors (mtIF) 2 and 3 in mitochondria. mtIF3 release from the ribosomal small subunit was believed to be a prerequisite for the recruitment of the initiator tRNA. Here we use cryogenic electron microscopy to characterize plant mitochondria pre-initiation complexes and to reveal how plant mtIF3 binds the initiator tRNA and facilitates its accommodation in the decoding center.