Involved in proteolysis and elastolysis (degradation of the host protein elastin). Has staphylolytic activity (degrades pentaglycine cross-links in cell wall peptidogylcan), preferring Gly-Gly-|-X substrates where X is Ala or Gly. Enhances the elastolytic but not proteolytic activity of elastase (lasB) and elastolytic activity of other proteases. Degradation of elastin is likely to contribute to the pathogenicity of P.aeruginosa. Binds 1 zinc ion per subunit. Belongs to the peptidase M23A family.