An 18-residue synthetic peptide with an amino acid sequence corresponding to the first zinc-finger domain of human immunodeficience virus type 2 nucleocapsid protein has been studied by one- and two-dimensional ¹H NMR spectroscopy. Complete sequence specific ¹H assignment was achieved through combined use of two-dimensional HOHAHA and NOESY techniques carried out at 278 K. We have found that this fragment binds zinc tightly and stoichiometrically in a wide pH range. Secondary structural elements were determined from qualitative analysis of NOESY spectra. It was observed that this complex adopts a compact, folded structure with the presence of both type I and type II ß-turns. This structure is very similar to that observed for other zinc finger peptides of this class. Furthermore, from pH titration study it was noted that this peptide gives two sets of NMR lines, indicating that this complex, unlike the other retroviral zinc finger sequence, exists in solution as two slowly interconverting folded conformations.