Abstract
RNA dependent RNA polymerase (RdRp) is one of the most versatile enzymes of RNA viruses that is indispensable for replicating the genome as well as for carrying out transcription. The core structural features of RdRps are conserved, despite the divergence in their sequences. The structure of RdRp resembles that of a cupped right hand and consists of fingers, palm and thumb subdomains. The catalysis involves the participation of conserved aspartates and divalent metal ions. Complexes of RdRps with substrates, inhibitors and metal ions provide a comprehensive view of their functional mechanism and offer valuable insights regarding the development of antivirals. In this article, we provide an overview of the structural aspects of RdRps and their complexes from the Group III, IV and V viruses and their structure-based phylogeny.
Highlights
RNA genomes dominate the world of viruses
The core RNA dependent RNA polymerase (RdRp) domain consists of the thumb, palm and the fingers subdomains that are primarily involved in template binding, polymerization, nucleoside triphosphate (NTP) entry and associated functions (Figure 1A)
In the segmented ss (−) RNA viruses, motif G is composed of a helix that interacts with the priming NTPs [56,62,66]
Summary
RNA genomes dominate the world of viruses. Their success results from the possibility of accommodating rapid changes via mutations, which aids in countering constant challenges imposed by the host physiology [1]. RdRps are multi-domain (α and β) proteins belonging to Structural Classification of Proteins (SCOP) class 2.7.7.48. They catalyze RNA-template dependent formation of phosphodiester bonds between ribonucleotides in the presence of divalent metal ions [4]. The host factors include translation factors, protein chaperones, RNA-modifying enzymes, and a few other cellular proteins. These together with the RdRps, constitute the viral replication complexes (VRCs) [3,9]. In many Group IV viruses, VRCs associate with the host membranes to protect the viral RNAs and help segregation of products and templates during replication [12,13].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
