Abstract:
Structural organization of HIV-1 integrase is based on a tetramer formed by two protein dimers. Within this tetramer, the catalytic domain of one subunit of the first dimer interacts with the N-terminal domain of the second dimer subunit. It is the tetrameric structure that allows both ends of the viral DNA to be correctly positioned relative to the cellular DNA and to realize catalytic functions of integrase, namely 3\'-processing and strand transfer. However, during the HIV-1 replicative cycle, integrase is responsible not only for the integration stage, it is also involved in reverse transcription and is necessary at the stage of capsid formation of the newly formed virions. It has been suggested that HIV-1 integrase is a structurally dynamic protein and its biological functions depend on its structure. Accordingly, studying interactions between the domains of integrase that provide its tetrameric structure is important for understanding its multiple functions. In this work, we investigated the role of three amino acids of the catalytic domain, I182, R187, and K188, located in the contact region of two integrase dimers in the tetramer structure, in reverse transcription and integration. It has been shown that the R187 residue is extremely important for formation of the correct integrase structure, which is necessary at all stages of its functional activity. The I182 residue is necessary for successful integration and is not important for reverse transcription, while the K188 residue, on the contrary, is involved in formation of the integrase structure, which is important for the effective reverse transcription.
摘要:
HIV-1整合酶的结构组织基于由两个蛋白质二聚体形成的四聚体。在这个四聚体中,第一二聚体的一个亚基的催化结构域与第二二聚体亚基的N末端结构域相互作用。它是四聚体结构,允许病毒DNA的两端相对于细胞DNA正确定位,并实现整合酶的催化功能,即3'处理和链传输。然而,在HIV-1复制周期中,整合酶不仅负责整合阶段,它也参与逆转录,并且在新形成的病毒体的衣壳形成阶段是必需的。有人认为HIV-1整合酶是一种结构动态的蛋白质,其生物学功能取决于其结构。因此,研究提供其四聚体结构的整合酶结构域之间的相互作用对于理解其多种功能很重要。在这项工作中,我们研究了催化结构域的三个氨基酸的作用,I182,R187和K188,位于四聚体结构中两个整合酶二聚体的接触区,逆转录和整合。已经表明R187残基对于形成正确的整合酶结构极为重要。这在其功能活动的所有阶段都是必要的。I182残基是成功整合所必需的,对于逆转录并不重要,而K188残留物,相反,参与整合酶结构的形成,这对于有效的逆转录很重要。