SCO Cytochrome Oxidase Deficient Homolog 2 (SCO2)

The deduced human SCO2 protein of 266 amino acids predicts an N-terminal mitochondrial targeting presequence of 41 amino acids. Human and yeast SCO polypeptides share the greatest identity in a core region, which lies between glycine-102 and glycine-242 in human SCO2. In this region the amino acid identity between the 2 human proteins (54%) is less than that between the 2 yeast proteins (73%).Moreover, human SCO2 and SCO1 show similar divergence from both yeast proteins suggesting that the 2 human genes are not orthologous to the 2 yeast genes, but rather are paralogous genes. Northern blot analysis detected SCO2 expression as a 0.9-kb transcript in all 12 human tissues examined, with strongest signals in heart, skeletal muscle, brain, liver, and kidney.