Title
How does a symmetric dimer recognize an asymmetric substrate? A substrate complex of HIV-1 protease
UMMS Affiliation
Department of Biochemistry and Molecular Pharmacology
Publication Date
2000-09-01
Document Type
Article
Subjects
Amino Acid Sequence; Binding Sites; Capsid; Crystallography, X-Ray; Dimerization; HIV Protease; HIV-1; Hydrogen Bonding; Models, Molecular; Peptide Fragments; Protein Conformation; Substrate Specificity; Water
Disciplines
Biochemistry, Biophysics, and Structural Biology | Pharmacology, Toxicology and Environmental Health
Abstract
The crystal structure of an actual HIV-1 protease-substrate complex is presented at 2.0 A resolution (R-value of 19.7 % (R(free) 23.3 %)) between an inactive variant (D25N) of HIV-1 protease and a long substrate peptide, Lys-Ala-Arg-Val-Leu-Ala-Glu-Ala-Met-Ser, which covers a full binding epitope of capsid(CA)-p2, cleavage site. The substrate peptide is asymmetric in both size and charge distribution. To accommodate this asymmetry the two protease monomers adopt different conformations burying a total of 1038 A(2) of surface area at the protease-substrate interface. The specificity for the CA-p2 substrate peptide is mainly hydrophobic, as most of the hydrogen bonds are made with the backbone of the peptide substrate. Two water molecules bridge the two monomers through the loops Gly49-Gly52 (Gly49'-Gly52') and Pro79'-Val82' (Pro79-Val82). When other complexes are compared, the mobility of these loops is correlated with the content of the P1 and P1' sites. Interdependence of the conformational changes allows the protease to exhibit its wide range of substrate specificity.
DOI of Published Version
10.1006/jmbi.2000.4018
Source
J Mol Biol. 2000 Sep 1;301(5):1207-20. Link to article on publisher's site
Journal/Book/Conference Title
Journal of molecular biology
Related Resources
PubMed ID
10966816
Repository Citation
Prabu-Jeyabalan M, Nalivaika EA, Schiffer CA. (2000). How does a symmetric dimer recognize an asymmetric substrate? A substrate complex of HIV-1 protease. Biochemistry and Molecular Pharmacology Publications. https://doi.org/10.1006/jmbi.2000.4018. Retrieved from https://escholarship.umassmed.edu/bmp_pp/92