Structure and assembly of a paramyxovirus matrix protein.
Many pleomorphic, lipid-enveloped viruses encode matrix proteins that direct their assembly and budding, but the mechanism of this process is unclear. We have combined X-ray crystallography and cryoelectron tomography to show that the matrix protein of Newcastle disease virus, a paramyxovirus and relative of measles virus, forms dimers that assemble into pseudotetrameric arrays that generate the membrane curvature necessary for virus budding. We show that the glycoproteins are anchored in the gaps between the matrix proteins and that the helical nucleocapsids are associated in register with the matrix arrays. About 90% of virions lack matrix arrays, suggesting that, in agreement with previous biological observations, the matrix protein needs to dissociate from the viral membrane during maturation, as is required for fusion and release of the nucleocapsid into the host's cytoplasm. Structure and sequence conservation imply that other paramyxovirus matrix proteins function similarly.
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2032, USA.
Anthony J
AJ
Battisti
Geng
G
Meng
Dennis C
DC
Winkler
Lori W
LW
McGinnes
Pavel
P
Plevka
Alasdair C
AC
Steven
Trudy G
TG
Morrison
Michael G
MG
Rossmann
D000818:Animals; D018360:Crystallography, X-Ray; D019281:Dimerization; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism; D008854:Microscopy, Electron; D018096:Mononegavirales / Q000648:ultrastructure; D009521:Newcastle Disease / Q000821:virology*; D009522:Newcastle disease virus / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure*; D019251:Nucleocapsid / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism; D014771:Virion / Q000737:chemistry / Q000254:growth & development; D014779:Virus Replication / Q000502:physiology
D006023:Glycoproteins; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D014764:Viral Proteins; C409209:nucleoprotein, Newcastle disease virus