Mitochondrial ribosome or mitoribosome is a protein complex that is active in mitochondria and functions as a riboprotein for translating mitochondrial mRNAs encoded in mtDNA. Mitoribosome, like cytoplasmatic ribosome, consists of two subunits — large (mtLSU) and small (mt-SSU). However, the ratio of rRNA/protein is different from cytoplasmic ribosome, mitoribosome consists of several specific proteins and less rRNAs.