Ribosome — mRNA / A-site / peptide exit
mRNA codon aminoacyl-tRNA release factor polypeptide
RF1 / RF2 specificity check
Shape mimicry: tRNA vs release factor

Translation Termination: Release Factor Mimicry (2D)

This 2D counterpart runs the same real termination logic as its 3D twin on a flat, easy-to-read stage: an mRNA strand scrolls through a schematic ribosome cross-section as aminoacyl-tRNAs deliver amino acids codon by codon, building a growing polypeptide chain, until a stop codon (UAA, UAG or UGA) reaches the A site. No tRNA reads a stop codon — a release factor shaped like one docks in its place instead, but only if its codon-reading loop actually matches: RF1 recognizes UAA and UAG, RF2 recognizes UAA and UGA. Toggle either factor off and test it against a codon it can't read, and the engine genuinely blocks termination — the ribosome stalls on the A site exactly as it would in a real cell, with only random near-cognate tRNA readthrough as an escape route, rather than faking a release. When a present RF does match, watch its GGQ motif hydrolyse the finished chain free and RF3·GTP eject it so the ribosome can recycle for another round. A live specificity-check panel and a shape-mimicry comparison make the underlying codon-vs-RF logic visible frame by frame.