Biochemical properties of a putative signal peptide peptidase from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1.

ABSTRACT: We have performed the first biochemical characterization of a putative archaeal signal peptide peptidase (SppA(Tk)) from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1. SppA(Tk), comprised of 334 residues, was much smaller than its counterpart from Escherichia coli (618 residues) and harbored a single predicted transmembrane domain near its N terminus. A truncated mutant protein without the N-terminal 54 amino acid residues (deltaN54SppA(Tk)) was found to be stable against autoproteolysis and was examined further. DeltaN54SppA(Tk) exhibited peptidase activity towards fluorogenic peptide substrates and was found to be highly thermostable. Moreover, the enzyme displayed a remarkable stability and preference for alkaline pH, with optimal activity detected at pH 10. DeltaN54Spp

SUBMITTER: Matsumi R 

PROVIDER: S-EPMC1251612 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature