The HIV-1 nef Protein Does Not Have Guanine Nucleotide Binding,GTPase,or Autophosphorylating Activities

Abstract

Recombinant HIV-1 Nef proteins with either thr-15 or ala-15 have been constructed and expressed in the T7 bacterial system. From the soluble portion of bacterial lysates both Nef(thr-15) and Nef(ala-15) have been purified to near homogeneity through 6 nondenaturing Chromatographic steps in the presence of MgCl₂. Neither purified proteins display the previously reported GTP binding activity. Additionally Nef(thr-15) does not have autophosphorylating activity with either [γ-³²P]GTP or [γ-³²P]ATP. Although GTPase activity is present in the preparations of Nef proteins, it does not increase during purification and is attributed to bacterial contaminations.