TABLE 11.2 Components required for protein synthesis in bacterial cells
Stage Component Function
tRNA charging

Amino acids

tRNAs

Aminoacyl-tRNA synthetases

ATP

Building blocks of proteins

Deliver amino acids to ribosomes

Attach amino acids to tRNAs

Provides energy for binding amino acids to tRNAs

Initiation

mRNA

fMet-tRNAfMet

30S ribosomal subunit

50S ribosomal subunit

Initiation factor 1

Initiation factor 2

Initiation factor 3

Carries coding instructions

Provides first amino acid in peptide

Attaches to mRNA

Stabilizes tRNAs and amino acids

Enhances dissociation of large and small subunits of ribosome

Binds GTP; delivers fMet-tRNAfMet to initiation codon

Binds to 30S subunit and prevents association with 50S subunit

Elongation

70S initiation complex

Charged tRNAs

Elongation factor Tu

Elongation factor Ts

Elongation factor G

GTP

rRNA in 50S ribosomal subunit

Functional ribosome with A, P, and E sites where protein synthesis takes place

Bring amino acids to ribosome and help assemble them in order specified by mRNA

Binds GTP and charged tRNA; delivers charged tRNA to A site

Regenerates active elongation factor Tu

Stimulates movement of ribosome to next codon

Provides energy

Creates peptide bond between amino acids in A site and P site

Termination Release factors 1, 2, and 3 Bind to ribosome when stop codon is reached and terminate translation