Cloning and identification of a novel tyrosinase and its overexpression in Streptomyces kathirae SC-1 for enhancing melanin production

A 30 kDa novel tyrosinase was purified to homogeneity. The K m for L-Dopa and L-tyrosine were determined as 0.42 mM and 0.25 mM. The 1231 bp (base pair) mel C gene and its 167 bp promoter Pskmel were obtained by Thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR) based on the amino acids fragment obtained from MS results of the purified enzyme. The protein sequence of tyrosinase shows maximum identity (84%) to tyrosinase from S. galbus . The mel C was introduced into S. kathirae . The melanin production and the transcriptional level of mel C in recombinant S. kathirae [pIJ Pskmel melC] were about 2.1-fold and two-fold higher than the wild-type strain, respectively. The melanin concentration was maximized at 28.8 g/L.