Translation in prokaryotes. Match each protein/factor to the role it plays: IF-1 (initiation Factor 1) [Choose]] Binds the mRNA and the initiation factors Brings IMet-tRNA to the complex and hydrolyzes GTP Blocks the A site on the ribosome Blocks the P site on the ribosome Blocks the 50 S subunit from binding until initiation is complete 50 S subunit Does not get added until the end of initiation; displaces the initiation factors 305 tsubunit IF.3 (0ritiation Factor 3).