Implication of RNase H domain on dimer stability and drug sensitivity of HIV-1 RT

描述（由申请人提供）：HIV-1 RT的连接亚结构域和RNA酶H结构域最近与对NRTI和NNRTI药物耐药的HIV-1毒株的出现有关。据报道，连接亚结构域和RNA酶H结构域中的位点特异性突变影响底物或NRTI结合亲和力和其他聚合酶相关性质，如持续合成能力，这表明聚合酶结构域和HIV-1 RT的这两个遥远的结构单元之间发生了决定性的长距离串扰。许多机制，包括RNA酶H切割活性的降低，这降低了模板转换，以及模板-引物底物的不适当定位来解释耐药突变。基于HIV-1 RT的三维结构，我们认为RNA酶H结构域C端的疏水残基与C端连接亚结构域的相互作用可能在亚基二聚化过程中起着重要的结构作用;这些区域中的任何突变变化都可能影响二聚体的稳定性和HIV-1的底物结合亲和力。1 RT。我们拟研究HIV-1 RT连接亚结构域和RNase H结构域界面处疏水残基突变对酶二聚体稳定性和药物敏感性的影响。我们还将包括在药物压力下出现的与RNase H相关的临床相关耐药突变。

DESCRIPTION (provided by applicant): The connection subdomain and RNase H domain of HIV-1 RT have recently been implicated in the emergence of HIV-1 strains that are resistant to NRTI and NNRTI drugs. Site-specific mutations in the connection subdomain and RNase H domain reportedly affect substrate or NRTI binding affinity and other polymerase-related properties such as processivity, suggesting that definitive long-distance cross-talk occurs between the polymerase domain and these two distantly located structural units of HIV-1 RT. Numerous mechanisms, including a reduction in RNase H cleavage activity, which decreased template switching, and improper positioning of template-primer substrate have been proposed to explain the drug-resistant mutations. Based on the three-dimensional (3D) structure of HIV-1 RT, we propose that hydrophobic residues at the C-terminal region of the RNase H domain interacting with the C-terminal connection subdomain may be structurally important in subunit dimerization; any mutational changes in these regions may affect dimer stability and the substrate binding affinity of HIV-1 RT. We propose to investigate the implications of mutations of hydrophobic residues at the interface of the connection subdomain and RNase H domain of HIV-1 RT with respect to dimer stability and drug sensitivity of the enzyme. We will also include clinically relevant drug-resistant mutations that emerge in connection and RNase H under drug pressure.