MRPS27 was annotated initially as one of the mammalian small subunit ribosomal proteins although its function was not known []. The supernumerary mitochondrial ribosomal protein of the small subunit 27 (MRPS27) is a pentatricopeptide repeat domain (PPR) protein required for mitochondrial protein synthesis [].
Mammalian pentatricopeptide repeat domain (PPR) proteins are involved in regulation of mitochondrial RNA metabolism and translation and are required for mitochondrial function. The supernumerary mitochondrial ribosomal protein of the small subunit 27 (MRPS27) is not required for mitochondrial RNA processing or the stability of the small ribosomal subunit. However, MRPS27 is required for mitochondrial protein synthesis [].Pentatricopeptide repeat-containing protein 2 (PTCD2) is a related mitochondrial PPR protein, although despite their similarity, they may not have the same function [, ]. PTCD2 has a role in mitochondrial RNA metabolism and downstream effects on mitochondrial translation [, ]. PTCD2 has been identified as a target for autoantibodies in neurodegenerative disease and is used as a biomarker for Alzheimer disease [].
