1. Role of the histidine residues of visna virus nucleocapsid protein in metal ion and DNA binding.
- Author
-
Morcock DR, Sowder RC 2nd, and Casas-Finet JR
- Subjects
- Alkylation, Amino Acid Sequence, Animals, Binding Sites, Cysteine chemistry, Histidine chemistry, In Vitro Techniques, Kinetics, Metals metabolism, Nucleocapsid genetics, Sheep, Spectrometry, Fluorescence, Spectrophotometry, Visna-maedi virus genetics, Zinc Fingers genetics, DNA, Viral metabolism, Nucleocapsid chemistry, Nucleocapsid metabolism, Visna-maedi virus metabolism
- Abstract
Zinc finger (ZF) domains in retroviral nucleocapsid proteins usually contain one histidine per metal ion coordination complex (Cys-X(2)-Cys-X(4)-His-X(4)-Cys). Visna virus nucleocapsid protein, p8, has two additional histidines (in the second of its two ZFs) that could potentially bind metal ions. Absorption spectra of cobalt-bound ZF2 peptides were altered by Cys alkylation and mutation, but not by mutation of the extra histidines. Our results show that visna p8 ZFs involve three Cys and one His in the canonical spacing in metal ion coordination, and that the two additional histidines appear to interact with nucleic acid bases in p8-DNA complexes.
- Published
- 2000
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