A conformational change in the adeno-associated virus type 2 capsid leads to the exposure of hidden VP1 N termini.
The complex infection process of parvoviruses is not well understood so far. An important role has been attributed to a phospholipase A2 domain which is located within the unique N terminus of the capsid protein VP1. Based on the structural difference between adeno-associated virus type 2 wild-type capsids and capsids lacking VP1 or VP2, we show via electron cryomicroscopy that the N termini of VP1 and VP2 are involved in forming globules inside the capsids of empty and full particles. Upon limited heat shock, VP1 and possibly VP2 become exposed on the outsides of full but not empty capsids, which is correlated with the disappearance of the globules in the inner surfaces of the capsids. Using molecular modeling, we discuss the constraints on the release of the globularly organized VP1-unique N termini through the channels at the fivefold symmetry axes outside of the capsid.
Kronenberg
Stephanie
S
Applied Tumor Virology, German Cancer Research Centre, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany.
Böttcher
Bettina
B
von der Lieth
Claus W
CW
Bleker
Svenja
S
Kleinschmidt
Jürgen A
JA
D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D000229:Dependovirus / Q000737:chemistry / Q000378:metabolism*; D006358:Hot Temperature; D008958:Models, Molecular; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D014779:Virus Replication
D036022:Capsid Proteins; C442553:VP2 protein, Dependovirus