哺乳动物线粒体核糖体蛋白质由核基因编码，有助于线粒体内蛋白质的合成线粒体核糖体（有丝分裂核糖体）由一个小的28s亚单位和一个大的39s亚单位组成。与原核核糖体相比，它们的蛋白质与核糖核酸的比例估计为75%，而原核核糖体的比例正好相反哺乳动物有丝分裂核糖体和原核核糖体的另一个区别是后者含有5srrna。在不同的物种中，包含有丝分裂核糖体的蛋白质在序列上有很大的差异，有时在生化性质上也有差异，这使得序列同源性很难识别该基因编码39s亚单位蛋白。[由RefSeq提供，2008年7月]
Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 39S subunit protein. [provided by RefSeq, Jul 2008]