The Structural Dynamics of Human Immunodeficiency Virus Type I Reverse Transcriptase
Author | : James Malcolm Seckler |
Publisher | : |
Total Pages | : 168 |
Release | : 2011 |
ISBN-10 | : OCLC:1159432096 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book The Structural Dynamics of Human Immunodeficiency Virus Type I Reverse Transcriptase written by James Malcolm Seckler and published by . This book was released on 2011 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human Immunodeficiency Virus Type 1 Reverse Transcriptase (RT) is the protein in HIV responsible for transcribing viral RNA into double stranded DNA, making it an essential component in viral infectivity and the most popular target for anti-viral therapies for HIV. Over the years, a plethora of inhibitors for RT have been developed, and many of them are currently approved for clinical use. Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTI) are small molecules that act as non-competitive, allosteric inhibitors of RT, binding in a binding pocket inside of the polymerase domain of RT and hampering enzymatic activity. Although this is a widely used class of viral inhibitor, the mechanism of inhibition is currently unknown. In addition to this, most current knowledge of RT is concentrated on the heterodimer, while little is known of the monomeric precursors to this structure. In this study we employ HXMS and SAXS to probe the solution structural dynamics and solution structure of RT heterodimer and monomers. We show that the p51 subunit does not form the stable core of the protein. Rather the core consists of the fingers and palm subdomains of both subunits. A ß-sheet that forms half of the NNRTI binding site undergoes slow cooperative unfolding, which is slowed by several orders of magnitude upon NNRTI binding. In addition to this, HXMS analysis reveals an allosteric network of regions that spans both subunits of the RT heterodimer. This network is thought to play a vital role in RT inhibition. The structural dynamics and solution structure of RT monomers were determined, revealing that the monomers were structured but more flexible in solution compared to the solution structure of the heterodimer. HXMS revealed that the monomers had nearly identical secondary structure, with the main difference being slow cooperative unfolding in the p66 thumb subdomain. SAXS revealed that both monomers exist in an ensemble of conformation. The polymerase domain of both monomers exists both in an open p66-like conformation, a closed p51-like conformation, and several unique conformations. This research lays the foundation for a novel method of drug screening and discovery.