MRPS27 is a protein in humans that is encoded by MRPS27 gene. RNA-binding component of the mitochondrial small ribosomal subunit (mt-SSU) that plays a role in mitochondrial protein synthesis. Stimulates mitochondrial mRNA translation of subunit components of the mitochondrial electron transport chain. Binds to the mitochondrial 12S rRNA (12S mt-rRNA) and tRNA(Glu). Involved also in positive regulation of cell proliferation and tumor cell growth.