Structure of the T=13 capsid of infectious pancreatic necrosis virus (IPNV)-a salmonid birnavirus
(2025) In Journal of Virology 99(2).- Abstract
Birnaviruses infect a broad range of vertebrate hosts, including fish and birds, and cause substantial economic losses in the fishery and livestock industries. The infectious pancreatic necrosis virus (IPNV), an aquabirnavirus, specifically infects salmonids. While structures on T=1 subviral particles of the birnaviruses, including IPNV, have been studied, structural insights into the infectious T=13 particles have been limited to the infectious bursal disease virus (IBDV), an avibirnavirus. Determining the capsid structure of the T=13 particle of IPNV is crucial for advancing knowledge of its antigenicity, capsid assembly, and possible functional structures. Here, the capsid structure of the IPNV L5 strain has been determined at a... (More)
Birnaviruses infect a broad range of vertebrate hosts, including fish and birds, and cause substantial economic losses in the fishery and livestock industries. The infectious pancreatic necrosis virus (IPNV), an aquabirnavirus, specifically infects salmonids. While structures on T=1 subviral particles of the birnaviruses, including IPNV, have been studied, structural insights into the infectious T=13 particles have been limited to the infectious bursal disease virus (IBDV), an avibirnavirus. Determining the capsid structure of the T=13 particle of IPNV is crucial for advancing knowledge of its antigenicity, capsid assembly, and possible functional structures. Here, the capsid structure of the IPNV L5 strain has been determined at a resolution of 2.75 Å. The overall structure resembles the T=13 IBDV structure, with notable differences in the surface loops on the P domain of the VP2 capsid protein essential for antigenicity and virulence. Additionally, previously undescribed structural features have been identified, including the C-terminal regions of the VP2 subunits within the pentagonal assembly unit at each 5-fold axis, which interlock with adjacent VP2 subunits. This interlocking, together with class-averaged projections of triangular and pentagonal units, suggests that the pentagonal unit formation could be important for a correct T=13 particle assembly, preventing the formation of T=1 subviral particles. Furthermore, positively charged residues in obstructed capsid pores at each 5-fold axis are speculated to facilitate intraparticle genome synthesis of IPNV.
(Less)
- author
- Munke, Anna
LU
; Ahmed Abdelrahim Gamil, Amr ; Mikalsen, Aase B ; Wang, Han ; Evensen, Øystein and Okamoto, Kenta
- publishing date
- 2025-02-25
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Infectious pancreatic necrosis virus, capsid structure, Animals, IPNV, virology, Birnaviridae, Fish Diseases, cryo-electron microscopy, cryo-EM
- in
- Journal of Virology
- volume
- 99
- issue
- 2
- article number
- e0145424
- publisher
- American Society for Microbiology
- external identifiers
-
- scopus:85219757289
- pmid:39817769
- ISSN
- 1098-5514
- DOI
- 10.1128/jvi.01454-24
- language
- English
- LU publication?
- no
- id
- 6d7a2960-6625-4a40-b83d-e8b6cbfbe516
- date added to LUP
- 2025-04-21 20:31:11
- date last changed
- 2025-07-01 10:28:26
@article{6d7a2960-6625-4a40-b83d-e8b6cbfbe516, abstract = {{<p>Birnaviruses infect a broad range of vertebrate hosts, including fish and birds, and cause substantial economic losses in the fishery and livestock industries. The infectious pancreatic necrosis virus (IPNV), an aquabirnavirus, specifically infects salmonids. While structures on T=1 subviral particles of the birnaviruses, including IPNV, have been studied, structural insights into the infectious T=13 particles have been limited to the infectious bursal disease virus (IBDV), an avibirnavirus. Determining the capsid structure of the T=13 particle of IPNV is crucial for advancing knowledge of its antigenicity, capsid assembly, and possible functional structures. Here, the capsid structure of the IPNV L5 strain has been determined at a resolution of 2.75 Å. The overall structure resembles the T=13 IBDV structure, with notable differences in the surface loops on the P domain of the VP2 capsid protein essential for antigenicity and virulence. Additionally, previously undescribed structural features have been identified, including the C-terminal regions of the VP2 subunits within the pentagonal assembly unit at each 5-fold axis, which interlock with adjacent VP2 subunits. This interlocking, together with class-averaged projections of triangular and pentagonal units, suggests that the pentagonal unit formation could be important for a correct T=13 particle assembly, preventing the formation of T=1 subviral particles. Furthermore, positively charged residues in obstructed capsid pores at each 5-fold axis are speculated to facilitate intraparticle genome synthesis of IPNV.</p>}}, author = {{Munke, Anna and Ahmed Abdelrahim Gamil, Amr and Mikalsen, Aase B and Wang, Han and Evensen, Øystein and Okamoto, Kenta}}, issn = {{1098-5514}}, keywords = {{Infectious pancreatic necrosis virus; capsid structure; Animals; IPNV; virology; Birnaviridae; Fish Diseases; cryo-electron microscopy; cryo-EM}}, language = {{eng}}, month = {{02}}, number = {{2}}, publisher = {{American Society for Microbiology}}, series = {{Journal of Virology}}, title = {{Structure of the T=13 capsid of infectious pancreatic necrosis virus (IPNV)-a salmonid birnavirus}}, url = {{http://dx.doi.org/10.1128/jvi.01454-24}}, doi = {{10.1128/jvi.01454-24}}, volume = {{99}}, year = {{2025}}, }