The present invention relates to a polypeptide with endolysin activity comprising an amino acid sequence according to SEQ ID No. 1 and fragments or derivatives thereof or fusion proteins derived thereof. Moreover the present invention relates to nucleic acid molecules encoding said polypeptide or fusion protein vectors comprising said nucleic acid molecules and host cells comprising either said nucleic acid molecules or said vectors. In addition the present invention relates to said polypeptide fragment derivative or fusion protein for use as a medicament in particular for the treatment or prevention of Gram negative bacterial infections as diagnostic means as cosmetic substance or as sanitizing agent. The present invention also relates to the use of said polypeptide fragment derivative or fusion protein for the treatment or prevention of Gram negative bacterial contamination of foodstuff of food processing equipment of food processing plants of surfaces coming into contact with foodstuff of medical devices of surfaces in hospitals and surgeries. Furthermore the present invention relates to a pharmaceutical composition comprising said polypeptide fragment derivative or fusion protein.
