3.4.16.6 E353Q cells infected with the mutant enzyme show considerable carboxypeptidase activity, mutation eliminates the activity of domain 1 647241 3.4.16.6 E771Q cells infected with the mutant enzyme show considerable carboxypeptidase activity, mutation eliminates the activity of domain 2 647241 3.4.16.6 additional information enzyme is encoded by silver gene svr. Mutant lines svrPG33 do not survive past the early larval stage, having a P-element insertion upstream of the initiation ATG. Mutant lines svr1 and svrpoi are viable, with silvery body color and poited wings. svr1 gene has a three-nucleotide deletion in exon 6, svrpoi has a 1072-bp duplication of the gene that introduces a stop codon into the open reading frame. Both mutations eliminate enzyme activity of the second carboxypeptidase-like domain, which reduces levels of the long forms of enzyme but does not affect the levels of the short forms 669448 3.4.16.6 additional information lack of the Kex1 protease results in fusion defects during yeast mating 683695 3.4.16.6 additional information studies of dependence of Saccharomyces cerevisiae K2 preprotoxin killing and immunity properties modulated by the action of Kex1p and Kex2p enzymes show that the lack of Kex1p carboxypeptidase 10times decreases toxin activity, and the deficiency of Kex2p endopeptidase completely removes killing ability 683223