Comparative genomics analysis of tyrosinases in Streptomyces species

Abstract

In Streptomyces, tyrosinase (EC 1.14.18.1) is associated with melanin synthesis, and encoded by the melC locus, which is a bicistronic operon that includes two genes (melC1 and melC2). MelC2 is the tyrosinase depends on the helper protein MelC1 in its activation. Genomic studies have detected the existence of a new bicistronic operon (melD), that encodes a putative tyrosinase in most Streptomyces species. Streptomyces coelicolor is the only specie previously known to have the melD operon but no melC operon in the chromosome sequences. A third homolog of the melC operon (griE - griF) homolog was detected only in S. griseus, and it participates in grixazone's biosynthesis. Tyrosinases MelD2 and GriF are not involved in melanin production.