Capsid assembly in a family of animal viruses primes an autoproteolytic maturation that depends on a single aspartic acid residue.
Capsid assembly in a family of animal viruses primes an autoproteolytic maturation that depends on a single aspartic acid residue.
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DOI：
10.1016/s0021-9258(17)36883-7
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发表时间：
1994-05
期刊：
影响因子：
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通讯作者：
A. Zlotnick;V. Reddy;R. Dasgupta;A. Schneemann;W. Ray;R. Rueckert;J. Johnson
中科院分区：
文献类型：
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作者：
A. Zlotnick;V. Reddy;R. Dasgupta;A. Schneemann;W. Ray;R. Rueckert;J. Johnson
非感染性诺达病毒的成熟是通过对构成二十面体衣壳的180个α蛋白拷贝中的大多数进行自身蛋白水解裂解而发生的。这种成熟比病毒组装慢得多，产生的感染性颗粒比供给物更稳定，并使病毒的脱包衣在热力学上与组装不同，允许在类似条件下进行组装和（时间延迟的）脱包衣。结构、计算和分子遗传学研究的结果表明，成熟既取决于亚基内菌株，在组装过程中产生，也取决于临界天冬氨酸残基。该残基位于疏水口袋中，通过亚基间接触稳定。它接近于可剪键，并表现出环境升高的pKa。在肽键的水解裂解过程中，一个酸性残基明显参与，而在酸性蛋白酶中，则有两个这样的残基参与。
Maturation of noninfectious nodavirus provirions occurs by autoproteolytic cleavage of most of the 180 copies of the alpha-protein that make up the icosahedral capsid. This maturation, which is much slower than viral assembly, produces an infectious particle that is more stable than the provirion and makes viral uncoating thermodynamically distinct from assembly, allowing assembly and (a time-delayed) uncoating to occur under similar conditions. The results of structural, computational, and molecular genetic studies suggest that maturation depends both on intrasubunit strain, produced during assembly, and on a critical aspartic acid residue. This residue lies in a hydrophobic pocket that is stabilized by intersubunit contacts. It is close to the scissile bond and exhibits an environmentally elevated pKa. The apparent involvement of a single acidic residue in the hydrolytic cleavage of a peptide bond contrasts with the involvement of 2 such residues in acid proteases.