2P3B: Crystal Structure Of The Subtype B Wild Type Hiv Protease Complexed With Tl-3 Inhibitor

Although a majority of HIV-1 infections in Brazil are caused by the subtype B virus (also prevalent in the United States and Western Europe), viral subtypes F and C are also found very frequently. Genomic differences between the subtypes give rise to sequence variations in the encoded proteins, including the HIV-1 protease. The current anti-HIV drugs have been developed primarily against subtype B and the effects arising from the combination of drug-resistance mutations with the naturally existing polymorphisms in non-B HIV-1 subtypes are only beginning to be elucidated. To gain more insights into the structure and function of different variants of HIV proteases, we have determined a 2.1 A structure of the native subtype F HIV-1 protease (PR) in complex with the protease inhibitor TL-3. We have also solved crystal structures of two multi-drug resistant mutant HIV PRs in complex with TL-3, from subtype B (Bmut) carrying the primary mutations V82A and L90M, and from subtype F (Fmut) carrying the primary mutation V82A plus the secondary mutation M36I, at 1.75 A and 2.8 A resolution, respectively. The proteases Bmut, Fwt and Fmut exhibit sevenfold, threefold, and 54-fold resistance to TL-3, respectively. In addition, the structure of subtype B wild type HIV-PR in complex with TL-3 has been redetermined in space group P6(1), consistent with the other three structures. Our results show that the primary mutation V82A causes the known effect of collapsing the S1/S1' pockets that ultimately lead to the reduced inhibitory effect of TL-3. Our results further indicate that two naturally occurring polymorphic substitutions in subtype F and other non-B HIV proteases, M36I and L89M, may lead to early development of drug resistance in patients infected with non-B HIV subtypes.
PDB ID: 2P3BDownload
MMDB ID: 45723
PDB Deposition Date: 2007/3/8
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 2.1  Å
Source Organism:
Similar Structures:
Biological Unit for 2P3B: dimeric; determined by author and by software (PISA)
Molecular Components in 2P3B
Label Count Molecule
Proteins (2 molecules)
Molecule annotation
Molecule annotation
Chemical (1 molecule)
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Citing MMDB