Structure of a Covalently Trapped Catalytic Complex of HIV-1 Reverse Transcriptase: Implications for Drug Resistance
Huifang Huang,
*
Rajiv Chopra,
*
Gregory L. Verdine,
Stephen C. Harrison
A combinatorial disulfide cross-linking strategy was used to
prepare a stalled complex of human immunodeficiency virus-type 1 (HIV-1) reverse transcriptase with a DNA template:primer and a
deoxynucleoside triphosphate (dNTP), and the crystal structure of the
complex was determined at a resolution of 3.2 angstroms. The presence
of a dideoxynucleotide at the 3'-primer terminus allows capture of a
state in which the substrates are poised for attack on the dNTP.
Conformational changes that accompany formation of the catalytic
complex produce distinct clusters of the residues that are altered in
viruses resistant to nucleoside analog drugs. The positioning of these
residues in the neighborhood of the dNTP helps to resolve some
long-standing puzzles about the molecular basis of resistance. The
resistance mutations are likely to influence binding or reactivity of
the inhibitors, relative to normal dNTPs, and the clustering of the
mutations correlates with the chemical structure of the drug.
H. Huang and G. L. Verdine are in the Department of Chemistry
and Chemical Biology, Harvard University, Cambridge, MA 02138, USA. R. Chopra and S. C. Harrison are at the Howard Hughes
Medical Institute and Department of Molecular and Cellular Biology,
Harvard University, Cambridge, MA 02138, USA.
*
These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail:
verdine{at}glviris.harvard.edu and schadmin{at}crystal.harvard.edu
