Nucleotide-dependent farnesyl switch orchestrates polymerization and membrane binding of human guanylate-binding protein 1

Significance In the human organism, guanylate-binding proteins (GBPs) are involved in antimicrobial and antiviral activity, but the mechanism of GBPs’ action remains poorly understood. We have discovered that binding of a substrate molecule, GTP, to the enzyme triggers the release of an aforemasked lipid anchor, which results in GBP polymerization on the one hand and in the attachment of GBPs to lipid membranes on the other. Thus, membrane...