Molecular characterization of Staphylococcus warneri catalase

The catalase gene was cloned by screening a genomic DNA library of S. warneri ISK-1 strain with a strong catalase activity for complementation of the activity in catalase-deficient E. coli strain. Nucleotide sequence analysis of a 2.2-kb DNA fragment revealed an open reading frame, called katA, encoding a peptide of 504 amino acids with a calculated molecular mass of 58kDa. The predicted amino acid sequence showed high similarities with the monofunctional catalases. No similarities were found between katA product and catalase-peroxidase type enzymes. Electrophoretic mobility of katA product was close to that of the previously purified ISK-1 catalase. Catalase activity was lost when the 135 amino acids were deleted from the C-terminal region.