Protein 15 is required for lysis in the presence of some divalent cations. Protein gp15 MSRIKAIIASVIICIIVCLSWAVNHYRDNAITYKEQRDKATSIIADMQKRQRDVAELDARYTKELADANATIETLRADVSAGRKRLQVSATCPKSTTGASGMGDGESPRLTADAELNYYRLRSGIDRITAQVNYLQEYIRSQCLK 15 145 ENPP_BPP22 Probable endopeptidase