BACTERIOPHAGE-LAMBDA LYSIS GENE-PRODUCT MODIFIED AND INSERTED INTO ESCHERICHIA-COLI OUTER-MEMBRANE - RZ1-LIPOPROTEIN

Lysis proteins of bacteriophage lambda were localized in different par ts of the host envelope: S in the inner membrane, (36)Rz in the membra ne adhesion sites, (14) and Rz1 in the outer membrane, The R gene prod uct, the transglycosylase destroying bacterial murein, is a soluble pr otein, Computer-assisted analysis of the Rz1 protein amino acids seque nce revealed that its N-terminal part contained the site (15)VVVG doub le down arrow C-20, which could be recognizable for the SPase II and c leaved leaving lipid modified C-20 as the N-terminal amino acid of the mature protein, Microsequencing of the Rz1 protein isolated from the expression products of E. coli [pSB54] carrying the Rz1 gene showed th at the N-terminal part of the protein was cleaved as predicted, Lipid labeling with [H-3]palmitate confirmed the expectation that Rz1 was a lipoprotein, E, coli [pSB54] treated with globomycin accumulated proli poprotein, the Rz1 precursor, which was detectable by the anti-Rz1 ser um on electropherograms as the 6.5-kDa protein, larger than mature pro tein, Physiological function of the Rz1 protein remains to be discover ed, but as a first hint we noticed that it evokes increase of the frac tion of adhesion sites of outer and inner membranes when overproduced from pSB54, The same effect was observed in induced E, coli (A) just b efore the lysis onset, however, one should be cautious in interpreting the results obtained in conditions of the overproduction of the Rz1 l ipoprotein.