1K2C

Combining Mutations in HIV-1 Protease to Understand Mechanisms of Resistance

Summary for 1K2C

• Entry DOI: 10.2210/pdb1k2c/pdb
• Related: 1A8K 1A94 1DAZ 1DW6 1K1T 1K1U 1K2B
• Related PRD ID: PRD_000349
• Descriptor: PROTEASE RETROPEPSIN, N-[(2R)-2-({N~5~-[amino(iminio)methyl]-L-ornithyl-L-valyl}amino)-4-methylpentyl]-L-phenylalanyl-L-alpha-glutamyl-L-alanyl-L-norleucinamide (3 entities in total)
• Functional Keywords: hiv-1 protease, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Human immunodeficiency virus 1
• Cellular location: Matrix protein p17: Virion (Potential). Capsid protein p24: Virion (Potential). Nucleocapsid protein p7: Virion (Potential). Reverse transcriptase/ribonuclease H: Virion (Potential). Integrase: Virion (Potential): P04587
• Total number of polymer chains: 2
• Total formula weight: 22288.33

Authors

Mahalingam, B.,Boross, P.,Wang, Y.-F.,Louis, J.M.,Fischer, C.,Tozser, J.,W Harrison, R.,Weber, I.T. (deposition date: 2001-09-26, release date: 2002-07-10, Last modification date: 2023-08-16)

Primary citation

Mahalingam, B.,Boross, P.,Wang, Y.F.,Louis, J.M.,Fischer, C.C.,Tozser, J.,Harrison, R.W.,Weber, I.T.
Combining mutations in HIV-1 protease to understand mechanisms of resistance.
Proteins, 48:107-116, 2002

PubMed Abstract: HIV-1 develops resistance to protease inhibitors predominantly by selecting mutations in the protease gene. Studies of resistant mutants of HIV-1 protease with single amino acid substitutions have shown a range of independent effects on specificity, inhibition, and stability. Four double mutants, K45I/L90M, K45I/V82S, D30N/V82S, and N88D/L90M were selected for analysis on the basis of observations of increased or decreased stability or enzymatic activity for the respective single mutants. The double mutants were assayed for catalysis, inhibition, and stability. Crystal structures were analyzed for the double mutants at resolutions of 2.2-1.2 A to determine the associated molecular changes. Sequence-dependent changes in protease-inhibitor interactions were observed in the crystal structures. Mutations D30N, K45I, and V82S showed altered interactions with inhibitor residues at P2/P2', P3/P3'/P4/P4', and P1/P1', respectively. One of the conformations of Met90 in K45I/L90M has an unfavorably close contact with the carbonyl oxygen of Asp25, as observed previously in the L90M single mutant. The observed catalytic efficiency and inhibition for the double mutants depended on the specific substrate or inhibitor. In particular, large variation in cleavage of p6(pol)-PR substrate was observed, which is likely to result in defects in the maturation of the protease from the Gag-Pol precursor and hence viral replication. Three of the double mutants showed values for stability that were intermediate between the values observed for the respective single mutants. D30N/V82S mutant showed lower stability than either of the two individual mutations, which is possibly due to concerted changes in the central P2-P2' and S2-S2' sites. The complex effects of combining mutations are discussed.

PubMed: 12012342
DOI: 10.1002/prot.10140

Experimental method

X-RAY DIFFRACTION (2.2 Å)