During the last few decades, the treatment of HIV-infected patients by highly active antiretroviral therapy, including protease inhibitors (PIs), has become standard. Here, we present results of analysis of a patient-derived, multiresistant HIV-1 CRF02_AG recombinant strain with a highly mutated protease (PR) coding sequence, where up to 19 coding mutations have accumulated in the PR. The results of biochemical analysis in vitro showed that the patient-derived PR is highly resistant to most of the currently used PIs and that it also exhibits very poor catalytic activity. Determination of the crystal structure revealed prominent changes in the flap elbow region and S1/S1' active site subsites. While viral loads in the patient were found to be high, the insertion of the patient-derived PR into a HIV-1 subtype B backbone resulted in reduction of infectivity by 3 orders of magnitude. Fitness compensation was not achieved by elevated polymerase (Pol) expression, but the introduction of patient-derived gag and pol sequences in a CRF02_AG backbone rescued viral infectivity to near wild-type (wt) levels. The mutations that accumulated in the vicinity of the processing sites spanning the p2/NC, NC/p1, and p6pol/PR proteins lead to much more efficient hydrolysis of corresponding peptides by patient-derived PR in comparison to the wt enzyme. This indicates a very efficient coevolution of enzyme and substrate maintaining high viral loads in vivo under constant drug pressure.

• MeSH
• Cell Line MeSH
• gag Gene Products, Human Immunodeficiency Virus genetics   MeSH
• pol Gene Products, Human Immunodeficiency Virus genetics   MeSH
• Genes, gag MeSH
• Genes, pol MeSH
• HEK293 Cells MeSH
• HIV Infections drug therapy   virology   MeSH
• HIV-1 genetics   isolation & purification   physiology   MeSH
• HIV Protease chemistry   genetics   metabolism   MeSH
• HIV Protease Inhibitors therapeutic use   MeSH
• Crystallography, X-Ray MeSH
• Humans MeSH
• Molecular Sequence Data MeSH
• Mutation MeSH
• Peptide Fragments genetics   MeSH
• Drug Resistance, Viral genetics   MeSH
• Viral Load MeSH
• Antiretroviral Therapy, Highly Active MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Names of Substances
• gag protein p1, Human immunodeficiency virus MeSH Browser
• gag Gene Products, Human Immunodeficiency Virus MeSH
• pol Gene Products, Human Immunodeficiency Virus MeSH
• HIV Protease MeSH
• HIV Protease Inhibitors MeSH
• p2 gag peptide, Human immunodeficiency virus 1 MeSH Browser
• Peptide Fragments MeSH