Summary information and primary citation

PDB-id
3klg; SNAP-derived features in text and JSON formats; DNAproDB
Class
transferase-DNA
Method
X-ray (3.65 Å)
Summary
Crystal structure of azt-resistant hiv-1 reverse transcriptase crosslinked to pre-translocation aztmp-terminated DNA (complex n)
Reference
Tu X, Das K, Han Q, Bauman JD, Clark AD, Hou X, Frenkel YV, Gaffney BL, Jones RA, Boyer PL, Hughes SH, Sarafianos SG, Arnold E (2010): "Structural basis of HIV-1 resistance to AZT by excision." Nat.Struct.Mol.Biol., 17, 1202-1209. doi: 10.1038/nsmb.1908.
Abstract
Human immunodeficiency virus (HIV-1) develops resistance to 3'-azido-2',3'-deoxythymidine (AZT, zidovudine) by acquiring mutations in reverse transcriptase that enhance the ATP-mediated excision of AZT monophosphate from the 3' end of the primer. The excision reaction occurs at the dNTP-binding site, uses ATP as a pyrophosphate donor, unblocks the primer terminus and allows reverse transcriptase to continue viral DNA synthesis. The excision product is AZT adenosine dinucleoside tetraphosphate (AZTppppA). We determined five crystal structures: wild-type reverse transcriptase-double-stranded DNA (RT-dsDNA)-AZTppppA; AZT-resistant (AZTr; M41L D67N K70R T215Y K219Q) RT-dsDNA-AZTppppA; AZTr RT-dsDNA terminated with AZT at dNTP- and primer-binding sites; and AZTr apo reverse transcriptase. The AMP part of AZTppppA bound differently to wild-type and AZTr reverse transcriptases, whereas the AZT triphosphate part bound the two enzymes similarly. Thus, the resistance mutations create a high-affinity ATP-binding site. The structure of the site provides an opportunity to design inhibitors of AZT-monophosphate excision.

Cartoon-block schematics in six views (download the tarball)

PyMOL session file Download PDB file View in 3Dmol.js