Guanylate Binding Protein 4 (GBP4)

Guanylate-binding proteins, such as GBP4, are induced by interferon and hydrolyze GTP to both GDP and GMP.Vestal (2005) reported that the 642-amino acid GBP4 protein shares 50 to 55% identity with GBP1 , GBP2 , and GBP5 . GBP4 contains a GTP-binding domain, but it lacks a C-terminal CaaX isoprenylation motif found in the other 3 GBPs.

Olszewski et al. (2006) found that GBP4 shares 74% and 81% amino acid identity with GBP6 and GBP7 , respectively. All GBPs, including GBP4, have a conserved N-terminal globular GTP-binding domain containing 2 consensus sequences and a third T(L/V)RD sequence not found in other GTPases. GBP4 has a unique 15-amino acid group at its N terminus that is not found in other GBPs.