![(A) Structure of a mature HIV-1 capsid (PDB: 3J3Y); CA hexamers (grey), and pentamers (blue). (B) Ultrastructure of the SARS-CoV-2 (EMD-30430); lipid envelope (grey), S protein (red) and RNPs (gold). (C) Structure of a mature HSV-1 (EMD-5452). The portal structure is shown in cyan and the surrounding hexagons are coloured in purple. (D) Model of the Ebola virus nucleocapsid obtained by applying helical symmetry to NP subunits (grey and purple) from recombinant virus-like particles (PDB: 6EHM and EMD-3871). (E) Central slice through a tomogram of a respiratory syncytial virus (RSV) filament (left). Crystal structure of the RSV matrix protein (PDB: 4V23) docked into a subtomogram average of the RSV matrix protein [71]; matrix protein (gold), subtomogram average (translucent grey) (right). (F) Composite structure showing the IAV M1 matrix protein (translucent grey and turquoise) (EMD-22384) forms the matrix layer over the RNP (not visible). Scale bar 10 nm. Figures were made using publicly available atomic coordinates and maps from the protein data bank (PDB) and Electron Microscopy Data Bank (EMDB) using UCSF ChimeraX (Pettersen et al. 2021).](https://port.silverchair-cdn.com/port/content_public/journal/biochemsoctrans/50/1/10.1042_bst20210433/3/bst-2021-0433c.01.png?Expires=1716520364&Signature=rv2nFiNCzsJ8sAuXSA7m~KgunQX8AMGT7diiN3DNy~qXs~AwR9ZTv10X5I-yaoyIvFRPS8weWwiDn2ROCR7aWNPU1FloNBgf~WbDSUogxF1Ds8AVbk8AWR0sdIVlqLEh1UGbE-jSpOBt-9VH1ERFP0SiUh49Abk0LiheHf3Qyf-eCEdkqV~LxQl-Eszr6GAkvWuHnqaTMHwTZdlp72mLu0nZyv0GDTKrKRk7DUP~PAqPF4RJfF2sPOFGJLY0FG~1DYuKgTi~4nKugVnBieFOVdW-M3ulTl6N2GbTpMfQ96L81RgPvlXEn0sbolmG~Dv93FSJ-ypZVydanP5xR1JVaQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
(A) Structure of a mature HIV-1 capsid (PDB: 3J3Y); CA hexamers (grey), and pentamers (blue). (B) Ultrastructure of the SARS-CoV-2 (EMD-30430); lipid envelope (grey), S protein (red) and RNPs (gold). (C) Structure of a mature HSV-1 (EMD-5452). The portal structure is shown in cyan and the surrounding hexagons are coloured in purple. (D) Model of the Ebola virus nucleocapsid obtained by applying helical symmetry to NP subunits (grey and purple) from recombinant virus-like particles (PDB: 6EHM and EMD-3871). (E) Central slice through a tomogram of a respiratory syncytial virus (RSV) filament (left). Crystal structure of the RSV matrix protein (PDB: 4V23) docked into a subtomogram average of the RSV matrix protein [71]; matrix protein (gold), subtomogram average (translucent grey) (right). (F) Composite structure showing the IAV M1 matrix protein (translucent grey and turquoise) (EMD-22384) forms the matrix layer over the RNP (not visible). Scale bar 10 nm. Figures were made using publicly available atomic coordinates and maps from the protein data bank (PDB) and Electron Microscopy Data Bank (EMDB) using UCSF ChimeraX (Pettersen et al. 2021).