Hepatitis B Virus Ribonuclease H: Mechanisms of Catalysis and Inhibition
Abstract
The proposed project was a biochemical analyses of the hepatitis B virus (HBV) ribonuclease H(RNaseH). RNaseH activity is essential for HBV replication and is a target of drug discovery,but RNaseH enzymology is very poorly understood. RNaseH catalysis requires Mg++ ions. Aim 1 asked How do Mg++ ions and the heteroduplex substrate interact with the RNaseH? Aim 2 asked How do RNaseH inhibitors interact with the RNaseH? These studies were stymied by unanticipated difficulties producing recombinant HBV RNaseH, so we changed focus to conduct similar studies on human RNase H1 (huRH1). We found that huRH1 inhibitors are unusual noncompetitive inhibitors that bind to the active site. We propose a model in which, by binding to the active site, huRH1 inhibitors stabilize an inactive enzyme substrate inhibitor complex to block enzyme function. We also predicted and validated the structure of the HBV polymerase, of which the HBV RNaseH is one domain. This breakthrough structure has strong mechanistic implications and has already launched 3 new drug discovery projects against HBV.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2022
- Accession Number
- AD1208678
Entities
People
- John E Tavis
Organizations
- Saint Louis University