CLONING AND SEQUENCE-ANALYSIS OF ZOOA, A STREPTOCOCCUS-ZOOEPIDEMICUS GENE ENCODING A BACTERIOCIN-LIKE INHIBITORY SUBSTANCE HAVING A DOMAIN-STRUCTURE SIMILAR TO THAT OF LYSOSTAPHIN

The nucleotide sequence has been determined for zooA, a gene encoding the bacteriocin-like inhibitory substance zoocin A in Streptococcus zo oepidemicus strain 4881. The, zooA gene product corresponds to the 285 -amino acid (aa) zoocin A pre-peptide from which a leader sequence is cleaved to form the 262-aa biologically active molecule of estimated m olecular mass 27 877 Da. Expression of zooA in a Gram-negative host wa s shown by the extracellular release from Escherichia coli, containing cloned zooA, of a biologically active peptide having an identical ran ge of anti-bacterial activity to that of zoocin A, purified from S. zo oepidemicus strain 4881. Data base searches revealed sequences having homologies with known muralytic proteins produced by both Grampositive and Gram-negative bacteria and indicate a 'mix and match' blending of domain-type structures, the C-terminal putative receptor-recognition region of the molecule being joined by a threonine-proline-rich linker to an N-terminal putative catalytic region having homology with sever al known endopeptidases, including lysostaphin. (C) 1997 Elsevier Scie nce B.V.