RT Journal Article
SR Electronic
T1 The Amino Acid Asn136 in HIV-1 Reverse Transcriptase (RT) Maintains Efficient Association of Both RT Subunits and Enables the Rational Design of Novel RT Inhibitors
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 49
OP 60
DO 10.1124/mol.105.012435
VO 68
IS 1
A1 Jan Balzarini
A1 Joeri Auwerx
A1 Fátima Rodríguez-Barrios
A1 Allel Chedad
A1 Viktor Farkas
A1 Francesca Ceccherini-Silberstein
A1 Carlos García-Aparicio
A1 Sonsoles Velázquez
A1 Erik De Clercq
A1 Carlo-Federico Perno
A1 María-José Camarasa
A1 Federico Gago
YR 2005
UL http://molpharm.aspetjournals.org/content/68/1/49.abstract
AB The highly conserved Asn136 is in close proximity to the nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI)-specific lipophilic pocket of human immunodeficiency virus type 1 (HIV-1) RT. Site-directed mutagenesis has revealed that the catalytic activity of HIV-1 RT mutated at position Asn136 is heavily compromised. Only 0.07 to 2.1% of wild-type activity is retained, depending on the nature of the amino acid change at position 136. The detrimental effect of the mutations at position 136 occurred when the mutated amino acid was present in the p51 subunit but not in the p66 subunit of the p51/p66 RT heterodimer. All mutant enzymes could be inhibited by second-generation NNRTIs such as efavirenz. They were also markedly more sensitive to the inactivating (denaturating) effect of urea than wild-type RT, and the degree of increased urea sensitivity was highly correlated with the degree of (lower) catalytic activity of the mutant enzymes. Replacing wild-type Asn136 in HIV-1 RT with other amino acids resulted in notably increased amounts of free p51 and p66 monomers. Our findings identify a structural/functional role for Asn136 in stabilization of the RT p66/p51 dimer and provide hints for the rational design of novel NNRTIs or drugs targeting either Asn136 in the β7–β8 loop of p51 or its anchoring point on p66 (the peptide backbone of His96) so as to interfere with the RT dimerization process and/or with the structural support that the p51 subunit provides to the p66 subunit and which is essential for the catalytic enzyme activity.