The code is read in three-letter words, codons; 64 of them spell 20 amino acids plus start and stop, and nearly all life uses the same code (Nirenberg & Matthaei 1961). The ribosome starts at AUG; adaptor tRNAs bring the amino acid that matches each codon, and the chain grows by a few amino acids every second (Ingolia et al. 2011). Established: Replicated many times; textbook knowledge.
The finished chain folds into a precise shape, and the shape is its job. Misfolded proteins are destroyed, and worn-out parts of the cell are recycled by autophagy. Because bacterial ribosomes differ slightly from ours, many antibiotics work by jamming them (Wilson 2014).
tRNAs bring the building blocks. Small adaptor RNAs, tRNAs, each carry one amino acid. A tRNA whose three letters pair with the codon delivers its amino acid, the ribosome joins it to the chain and moves on one codon, a few times every second.
In my research: Protein folding, the ER and autophagy →
Sources
- Nirenberg MW, Matthaei JH (1961) The dependence of cell-free protein synthesis in E. coli upon naturally occurring or synthetic polyribonucleotides. PNAS 47:1588–1602. doi:10.1073/pnas.47.10.1588
- Ingolia NT, Lareau LF, Weissman JS (2011) Ribosome profiling of mouse embryonic stem cells reveals the complexity and dynamics of mammalian proteomes. Cell 147:789–802. doi:10.1016/j.cell.2011.10.002
- Wilson DN (2014) Ribosome-targeting antibiotics and mechanisms of bacterial resistance. Nature Reviews Microbiology 12:35–48. doi:10.1038/nrmicro3155