Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health, National Institutes of Health, Bethesda, MD 20892-2780, USA.
Virology. 2011 Dec 20;421(2):253-65. doi: 10.1016/j.virol.2011.09.012. Epub 2011 Oct 26.
The HIV-1 capsid protein consists of two independently folded domains connected by a flexible peptide linker (residues 146-150), the function of which remains to be defined. To investigate the role of this region in virus replication, we made alanine or leucine substitutions in each linker residue and two flanking residues. Three classes of mutants were identified: (i) S146A and T148A behave like wild type (WT); (ii) Y145A, I150A, and L151A are noninfectious, assemble unstable cores with aberrant morphology, and synthesize almost no viral DNA; and (iii) P147L and S149A display a poorly infectious, attenuated phenotype. Infectivity of P147L and S149A is rescued specifically by pseudotyping with vesicular stomatitis virus envelope glycoprotein. Moreover, despite having unstable cores, these mutants assemble WT-like structures and synthesize viral DNA, although less efficiently than WT. Collectively, these findings demonstrate that the linker region is essential for proper assembly and stability of cores and efficient replication.
HIV-1 衣壳蛋白由两个独立折叠的结构域通过一个柔性肽连接体（残基 146-150）连接而成，其功能尚待确定。为了研究该区域在病毒复制中的作用，我们在每个连接体残基和两个侧翼残基上进行了丙氨酸或亮氨酸取代。鉴定出了三类突变体：（i）S146A 和 T148A 表现得像野生型（WT）；（ii）Y145A、I150A 和 L151A 无感染性，组装出具有异常形态的不稳定核心，几乎不合成病毒 DNA；（iii）P147L 和 S149A 表现出低感染性、减毒表型。P147L 和 S149A 的感染性可通过水疱性口炎病毒包膜糖蛋白假型化特异性恢复。此外，尽管这些突变体的核心不稳定，但它们组装出 WT 样结构并合成病毒 DNA，尽管效率低于 WT。总的来说，这些发现表明连接区对于核心的正确组装和稳定性以及有效的复制是必不可少的。
