A Secretion Signal Is Present in the Collybia velutipes Oxalate Decarboxylase Gene

Abstract

The oxalate decarboxylase (OXDC) gene from Collybia velutipes is overexpressed as an active form in Schizosaccharomyces pombe. The recombinant enzyme shows similar pH optima and stability, while substrate kinetic analysis shows a ninefold decrease in Km value with respect to native OXDC. Most of the expressed protein was present in periplasm and remained firmly bound to cell-wall materials. However, 20% of enzyme expressed was secreted out into the medium suggesting the presence of a secretion signal (C. velutipes) in the oxalate decarboxylase gene. This secretion signal is associated with the N-terminal of OXDC as is evident by secretion of nonsecretory genes AmA1 and β-galactosidase. An expression vector using this signal is constructed for expression and secretion of heterologous proteins in S. pombe.