Catalyzes the transfer of the diacylglyceryl group from phosphatidylglycerol to the sulfhydryl group of the N-terminal cysteine of a prolipoprotein, the first step in the formation of mature lipoproteins. 1,2-diacyl-sn-glycero-3-phospho-(1'-sn-glycerol) + L-cysteinyl-[prolipoprotein] = H(+) + S-1,2-diacyl-sn-glyceryl-L-cysteinyl-[prolipoprotein] + sn-glycerol 1-phosphate Inhibited by palmitate. Protein modification; lipoprotein biosynthesis (diacylglyceryl transfer). Contains several lipid molecules that are bound within the central cavity of the protein. Mutants are defective in diacylglyceryl modification of prolipoprotein. Belongs to the Lgt family.