This family consists of several tyrosinase co-factor MELC1 proteins from a number of Streptomyces species. The melanin operon (melC) of Streptomyces antibioticus contains two genes, melC1 and melC2 (apotyrosinase). It is thought that MelC1 forms a transient binary complex with the downstream apotyrosinase MelC2 to facilitate the incorporation of copper ion and the secretion of tyrosinase indicating that MelC1 is a chaperone for the apotyrosinase MelC2 [1].

1: Mutational study of Streptomyces tyrosinase trans-activator MelC1. MelC1 is likely a chaperone for apotyrosinase. Chen LY, Chen MY, Leu WM, Tsai TY, Lee YH; J Biol Chem 1993;268:18710-18716. PMID:8360164