N-Terminal domain of HTLV-I integrase. Complexation and conformational studies of the zinc finger. |
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Authors: | F Bertola C Manigand P Picard M Goetz J M Schmitter G Precigoux |
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Institution: | Unité de Biophysique Structurale, UMR 5471 CNRS, Université Bordeaux, France. |
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Abstract: | The HTLV-I integrase N-terminal domain 50-residue peptide (IN50)], and a 35-residue truncated peptide formed by residues 9-43 (IN35) have been synthesized by solid-phase peptide synthesis. Formation of the 50-residue zinc finger type structure through a HHCC motif has been proved by UV-visible absorption spectroscopy. Its stability was demonstrated by an original method using RP-HPLC. Similar experiments performed on the 35-residue peptide showed that the truncation does not prevent zinc complex formation but rather that it significantly influences its stability. As evidenced by CD spectroscopy, the 50-residue zinc finger is unordered in aqueous solution but adopts a partially helical conformation when trifluoroethanol is added. These results are in agreement with our secondary structure predictions and demonstrate that the HTLV-I integrase N-terminal domain is likely to be composed of an helical region (residues 28-42) and a beta-strand (residues 20-23), associated with a HHCC zinc-binding motif. Size-exclusion chromatography showed that the structured zinc finger dimerizes through the helical region. |
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Keywords: | HTLV‐I integrase peptide synthesis solution structure zinc finger |
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