6R3A

BACTERIOPHAGE SPP1 MATURE CAPSID PROTEIN

Summary for 6R3A

• Entry DOI: 10.2210/pdb6r3a/pdb
• EMDB information: 2049 4716
• Descriptor: Major capsid protein (1 entity in total)
• Functional Keywords: bacteriophage, capsid protein, image processing, virus
• Biological source: Bacillus phage SPP1
• Total number of polymer chains: 7
• Total formula weight: 246808.98

Authors

Ignatiou, A.,El Sadek Fadel, M.,Buerger, J.,Mielke, T.,Topf, M.,Tavares, P. (deposition date: 2019-03-19, release date: 2019-10-23, Last modification date: 2024-05-15)

Primary citation

Ignatiou, A.,Brasiles, S.,El Sadek Fadel, M.,Burger, J.,Mielke, T.,Topf, M.,Tavares, P.,Orlova, E.V.
Structural transitions during the scaffolding-driven assembly of a viral capsid.
Nat Commun, 10:4840-4840, 2019

PubMed Abstract: Assembly of tailed bacteriophages and herpesviruses starts with formation of procapsids (virion precursors without DNA). Scaffolding proteins (SP) drive assembly by chaperoning the major capsid protein (MCP) to build an icosahedral lattice. Here we report near-atomic resolution cryo-EM structures of the bacteriophage SPP1 procapsid, the intermediate expanded procapsid with partially released SPs, and the mature capsid with DNA. In the intermediate state, SPs are bound only to MCP pentons and to adjacent subunits from hexons. SP departure results in the expanded state associated with unfolding of the MCP N-terminus and straightening of E-loops. The newly formed extensive inter-capsomere bonding appears to compensate for release of SPs that clasp MCP capsomeres together. Subsequent DNA packaging instigates bending of MCP A domain loops outwards, closing the hexons central opening and creating the capsid auxiliary protein binding interface. These findings provide a molecular basis for the sequential structural rearrangements during viral capsid maturation.

PubMed: 31649265
DOI: 10.1038/s41467-019-12790-6

Experimental method

ELECTRON MICROSCOPY (4 Å)