Mitochondrial ribosomal protein L3

Mitochondrial ribosomal protein L3 is a protein that in humans is encoded by the MRPL3 gene. The MRPL3 gene encodes a protein of the 39S large subunit of the mitoribosome, which belongs to the L3P ribosomal protein family. Additionally, a pseudogene corresponding to this gene is located on chromosome 13q. .

Mitoribosome

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and play a crucial role in protein synthesis within the mitochondrion. Mitoribosomes consist of a small 28S subunit and a large 39S subunit. Unlike prokaryotic ribosomes, mitoribosomes are composed of approximately 75% protein and 25% rRNA, whereas this ratio is reversed in prokaryotic ribosomes. Another key difference is the absence of 5S rRNA in mammalian mitoribosomes, which is present in their prokaryotic counterparts. The proteins that comprise the mitoribosome differ greatly in sequence and, in some cases, in biochemical properties across different species. This variability complicates identification by sequence homology.

Mutations in this gene have been shown to cause mitochondrial cardiomyopathy.