7NS0

Bacilladnavirus capsid structure

This is a non-PDB format compatible entry.

Summary for 7NS0

• Entry DOI: 10.2210/pdb7ns0/pdb
• EMDB information: 12554
• Descriptor: Capsid protein VP2 (1 entity in total)
• Functional Keywords: jelly-roll, capsid, virus
• Biological source: Chaetoceros tenuissimus DNA virus type-II
• Total number of polymer chains: 3
• Total formula weight: 129988.68

Authors

Munke, A.,Okamoto, K. (deposition date: 2021-03-05, release date: 2022-07-20, Last modification date: 2024-07-10)

Primary citation

Munke, A.,Kimura, K.,Tomaru, Y.,Wang, H.,Yoshida, K.,Mito, S.,Hongo, Y.,Okamoto, K.
Primordial Capsid and Spooled ssDNA Genome Structures Unravel Ancestral Events of Eukaryotic Viruses.
Mbio, 13:e0015622-e0015622, 2022

PubMed Abstract: Marine algae viruses are important for controlling microorganism communities in the marine ecosystem and played fundamental roles during the early events of viral evolution. Here, we have focused on one major group of marine algae viruses, the single-stranded DNA (ssDNA) viruses from the family. We present the capsid structure of the bacilladnavirus DNA virus type II (CtenDNAV-II), determined at 2.4-Å resolution. A structure-based phylogenetic analysis supported the previous theory that bacilladnaviruses have acquired their capsid protein via horizontal gene transfer from a ssRNA virus. The capsid protein contains the widespread virus jelly-roll fold but has additional unique features; a third β-sheet and a long C-terminal tail. Furthermore, a low-resolution reconstruction of the CtenDNAV-II genome revealed a partially spooled structure, an arrangement previously only described for dsRNA and dsDNA viruses. Together, these results exemplify the importance of genetic recombination for the emergence and evolution of ssDNA viruses and provide important insights into the underlying mechanisms that dictate genome organization. Single-stranded DNA (ssDNA) viruses are an extremely widespread group of viruses that infect diverse hosts from all three domains of life, consequently having great economic, medical, and ecological importance. In particular, bacilladnaviruses are highly abundant in marine sediments and greatly influence the dynamic appearance and disappearance of certain algae species. Despite the importance of ssDNA viruses and the last couple of years' advancements in cryo-electron microscopy, structural information on the genomes of ssDNA viruses remains limited. This paper describes two important achievements: (i) the first atomic structure of a bacilladnavirus capsid, which revealed that the capsid protein gene presumably was acquired from a ssRNA virus in early evolutionary events; and (ii) the structural organization of a ssDNA genome, which retains a spooled arrangement that previously only been observed for double-stranded viruses.

PubMed: 35856561
DOI: 10.1128/mbio.00156-22

Experimental method

ELECTRON MICROSCOPY (2.4 Å)