Related Experiment Video
Updated: Jul 10, 2025

Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
Structural insights into the assembly and mechanism of mpox virus DNA polymerase complex F8-A22-E4-H5
Xiaohan Wang1, Liangwen Ma2, Ningning Li2
1State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
Abstract:
The DNA replication of mpox virus is performed by the viral polymerase F8 and also requires other viral factors, including processivity factor A22, uracil DNA glycosylase E4, and phosphoprotein H5. However, the molecular roles of these viral factors remain unclear. Here, we characterize the structures of F8-A22-E4 and F8-A22-E4-H5 complexes in the presence of different primer-template DNA substrates. E4 is located upstream of F8 on the template single-stranded DNA (ssDNA) and is catalytically active, highlighting a functional coupling between DNA base-excision repair and DNA synthesis. Moreover, H5, in the form of tetramer, binds to the double-stranded DNA (dsDNA) region downstream of F8 in a similar position as PCNA (proliferating cell nuclear antigen) does in eukaryotic polymerase complexes. Omission of H5 or disruption of its DNA interaction showed a reduced synthesis of full-length DNA products. These structures provide snapshots for the working cycle of the polymerase and generate insights into the mechanisms of these essential factors in viral DNA replication.
More Related Videos
08:53Strand-Specific Analysis of Proteins at Replicating DNA Strands by Enrichment and Sequencing of Protein-Associated Nascent DNA Method
Published on: May 2, 2025
08:55Characterization of Multi-subunit Protein Complexes of Human MxA Using Non-denaturing Polyacrylamide Gel-electrophoresis
Published on: October 28, 2016
Related Concept Videos
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
The Replisome
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
Eukaryotic RNA Polymerases
All three eukaryotic RNAPs require specific transcription factors, of which the...
Transcription Initiation
The promoters and enhancers and their accessory proteins allow tight regulation of...
Restarting Stalled Replication Forks
Translesion DNA Polymerases
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...