Human T-lymphotrophic virus type I nucleocapsid protein NCp15: structural study and stability of the N-terminal zinc-finger.
An 18-residue peptide, corresponding to the minimum sequence of the N-terminal zinc-finger domain in the nucleocapsid of human T-lymphotrophic virus type I, was synthesized by a solid-phase method and fully characterized. Its ability to complex metal ions (Co(2+) and Zn(2+)) was clearly established by UV-visible spectroscopy and MS. The stability of these complexes was investigated by an original method with HPLC chromatography. Our results show that, even in the presence of air, the Zn(2+) complex is highly stable. In contrast, the Co(2+) complex undergoes a relatively fast degradation due to an intramolecular oxidation leading to the formation of a disulphide bridge between two cysteine residues. The (1)H-NMR analysis indicates that Zn(2+) binds to the Ndelta atom of the histidine residue rather than to the Nepsilon atom. Two-dimensional NMR techniques were used to determine the solution structure of the zinc-finger, illustrated by the existence of turns in the overall conformation.
Bertola
F
F
Unité de Biophysique Structurale, UMR 5471 CNRS, Bât B8, avenue des Facultés, Université de Bordeaux I, 33405 Talence Cedex, France.
Manigand
C
C
Picard
P
P
Belghazi
M
M
Precigoux
G
G
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D015368:Human T-lymphotropic virus 1 / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry; D011487:Protein Conformation; D013057:Spectrum Analysis; D016335:Zinc Fingers
D008670:Metals; D019590:Nucleocapsid Proteins; D010446:Peptide Fragments