Comparison between larger and smaller subunit of ribosome

By: Prof. Dr. Fazal Rehman Shamil | Last updated: February 3, 2024

Let me share with you a comparison between larger and smaller subunit of ribosome.

AspectLarger Subunit Smaller Subunit
CompositionContains rRNA and proteinsContains rRNA and fewer proteins
Ribosomal RNA (rRNA)·        Includes 23S (bacteria and archaea)

·        28S (eukaryotes), 5S and 5.8S rRNA

·        Includes 16S (bacteria and archaea)

·        18S (eukaryotes) rRNA

Protein ContentNumerous proteins, more complex structureFewer proteins, relatively simpler structure
FunctionCatalyzes peptide bond formation during protein synthesisHelps in the decoding of mRNA and initiation of protein synthesis
Binding SitesContains P (peptidyl), A (aminoacyl) and E (exit) sitesContains mRNA binding site, tRNA binding sites (A, P, E sites) and initiation factors
Size (Svedberg units)·        50S in bacteria and archaea

·        60S in eukaryotes

·        30S in bacteria and archaea

·        40S in eukaryotes

Ribosomal Proteins·        L1, L2, L3, etc.·        S1, S2, S3, etc.