N-Terminal domain of HTLV-I integrase. Complexation and conformational studies of the zinc finger.
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.
Bertola
F
F
Unité de Biophysique Structurale, UMR 5471 CNRS, Université Bordeaux, France.
Manigand
C
C
Picard
P
P
Goetz
M
M
Schmitter
J M
JM
Precigoux
G
G
D000595:Amino Acid Sequence; D004795:Enzyme Stability; D015368:Human T-lymphotropic virus 1 / Q000201:enzymology*; D019426:Integrases / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary / Q000502:physiology; D016415:Sequence Alignment; D016335:Zinc Fingers
D010446:Peptide Fragments; D019426:Integrases