Structure
of
eukaryotic ribosomes
Ribosome subunits comprise
one or
two rRNA molecules,
plus a
variable number of proteins.
Combinations of rRNAs and
proteins
typically have a smaller sedimentation
rate (S)
than their
component parts, due to condensation. In
eukaryotes, the complete 80S
monosome
comprises a 40S Small Subunit
(SSU)
that includes the 18S rRNA,
and a 60S Large Subunit
(LSU)
that includes the 28S and
5S
rRNAs.