Structural investigation on the requirement of CCHH zinc finger type in nucleocapsid protein of human immunodeficiency virus 1.
The nucleocapsid proteins (NCps) of lentiviruses play a key role during the retroviral replication cycle. NCps contain one or two highly conserved domains characterized by a CX(2)CX(4)HX(4)C sequence which binds zinc with a high affinity. The reasons of the high conservation of zinc fingers of CCHC type in lentiviruses were investigated by a structural study of mutants in which the zinc-coordinated ligands were exchanged. The HCHC form was unable to bind zinc tetrahedrally, whereas in His(28)(13-30)NCp7 corresponding to the CCHH motif, the zinc was tightly complexed. The mutant peptide exists in two interconverting conformations E and D [DeltaG(DE) (293K) = 0.1 kcal/mol] arising from the zinc coordination of His(28), by either its Nepsilon2 or its Ndelta1, respectively. As compared to the native CCHC zinc finger, the Cys(28) --> His mutation induces structural changes in the finger due to a modification in the coordination state of His(23) bound to zinc by Nepsilon2 in the wild-type finger by Ndelta1 in both conformers of the mutant. Introduction of these single mutations within the NCp7 proximal zinc finger in the HIV-1 genome was very recently shown to result in a loss of viral infection. This supports the hypothesis that structural changes of the zinc finger domain of NCp7 inhibit the recognition of one or several targets critically involved in the virus life cycle.
Ramboarina
S
S
Département de Pharmacochimie Moléculaire et Structurale, INSERM U266-CNRS UMR 8600, Paris, France.
Morellet
N
N
Fournié-Zaluski
M C
MC
Roques
B P
BP
Moreller
N
N
D000595:Amino Acid Sequence; D002213:Capsid / Q000737:chemistry* / Q000235:genetics; D036022:Capsid Proteins; D015683:Gene Products, gag / Q000737:chemistry* / Q000235:genetics; D015497:HIV-1 / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013329:Structure-Activity Relationship; D014764:Viral Proteins; D015032:Zinc / Q000737:chemistry; D016335:Zinc Fingers / Q000235:genetics; D054301:gag Gene Products, Human Immunodeficiency Virus
D036022:Capsid Proteins; D015683:Gene Products, gag; C071884:NCP7 protein, Human immunodeficiency virus 1; D011994:Recombinant Proteins; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; D006639:Histidine; D015032:Zinc