The extracellular hyaluronidase gene (hylA) of Streptococcus pyogenes

Group A streptococci produce an extracellular hyaluronidase (hyaluronate lyase) which may be associated with the spread of the organism during infection. The gene for this hyaluronidase (hylA) encodes an 868 amino acid protein with a molecular size of 99636 Da. Cleavage of the proposed signal peptide results in an extracellular protein of 95941 Da. Comparison with other bacterial hyaluronidases indicates strong similarities to the genes from Streptococcus pneumoniae, Streptococcus agalactiae and Staphylococcus aureus. A region internal to the hylA gene was amplified from all 175 strains of Streptococcus pyogenes tested suggesting a widespread distribution of the gene.