A conserved leucine that constricts the pore through the capsid fivefold cylinder plays a central role in parvoviral infection

被引:57
作者
Farr, GA
Tattersall, P
机构
[1] Yale Univ, Sch Med, Dept Lab Med, New Haven, CT 06510 USA
[2] Yale Univ, Sch Med, Dept Lab Med & Genet, Grad Program Microbiol, New Haven, CT 06510 USA
[3] Yale Univ, Sch Med, Dept Genet, New Haven, CT 06510 USA
关键词
MVM; parvovirus; virion structure; fivefold cylinder; capsid assembly; DNA packaging; viral entry; portal; maturation cleavage;
D O I
10.1016/j.virol.2004.03.006
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
The atomic structure of the DNA-containing T = 1 particle of the parvovirus minute virus of mice (MVM) reveals cylindrical projections at each fivefold symmetry axis, each containing an 8 Angstrom pore through which runs 10 amino acids of a single VP2 N-tenninus. The tightest constriction of this pore is formed at its inner end by the juxtaposition of leucine side chains from position 172 of five independent VP2 molecules. To test whether L172 modulates the extrusion of VP N-termini, we constructed and analyzed a complete set of amino acid substitution mutants at this highly conserved residue. All but one mutant produced DNA-containing virions, but only two, L172V and L 1721, were infectious, the others being blocked for viral entry. Several mutants were significantly defective for assembly at 39 degreesC, but not at 32 degreesC. L172W significantly impaired genome encapsidation, indicating that the fivefold cylinder may also be the DNA packaging portal. Although tryptic cleavage of the `VP2 N-tenninus was not affected for the mutants, VP1 was degraded during proteolysis of mutant, but not wild-type, virions. (C) 2004 Elsevier Inc. All rights reserved.
引用
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页码:243 / 256
页数:14
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