STRUCTURE AND FUNCTION OF BACTERIAL RECQ PROTEIN

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 RecQ是一种多组分酶，是一种ATP依赖性DNA解旋酶。三种人类综合征，布鲁姆综合征，沃纳综合征和罗斯蒙-汤普森综合征，分别由密切相关的BLM，WRN和RECQ 4 recQ基因内的突变引起，突出了RecQ蛋白质家族的重要性。RecQ的一个亚结构域含有翼螺旋（WH）结构基序，其含有与双链DNA（dsDNA）和一对侧翼β-链（形成“翼”）进行广泛的大沟接触的识别α-螺旋，所述侧翼β-链通常在dsDNA的小沟侧上相互作用。 已知RecQ解旋酶的WH结构域及其变体结合多种DNA底物，并且还被认为是蛋白质-蛋白质相互作用结构域。 已经提出RecQ的该亚结构域可以与多个关键蛋白质瞬时相互作用，从而介导DNA复制、重组和修复机制。有证据表明WH结构域紧密且特异性地结合至单链DNA结合（SSB）蛋白的C末端。 此外，SSB蛋白的C-末端结构域在与ssDNA结合时是无序的（Savvides等人，2004），因此这种蛋白质-蛋白质相互作用可能对于调节SSB功能以及可能调节RecQ的酶活性至关重要。 这项合作（Keck和Butcher实验室之间）的目标是通过NMR光谱法绘制RecQ解旋酶的WH结构域与SSB蛋白C末端内的关键10个氨基酸之间的蛋白质-蛋白质相互作用。此外，我们的目标是确定的ssDNA，dsDNA，和SSB结合位点的WH结构域的E。Coli RecQ蛋白。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. RecQ is a multi-component enzyme and is an ATP-dependent DNA helicase. Three human syndromes, Bloom's, Werner's, and Rothmun-Thompson's syndromes, arise from mutations within the closely related BLM, WRN, and RECQ4 recQ genes, respectively, highlighting the importance of the RecQ family of proteins. One of the sub-domains of RecQ contains a winged-helix (WH) structural motif, containing a recognition alpha-helix which makes extensive major groove contacts with double stranded DNA (dsDNA) and a pair of flanking beta-strands (forming the "wing"), which typically interact on the minor groove side of dsDNA. The WH domain of RecQ helicases and its variants are known to bind a variety of DNA substrates and has also been implicated as a protein-protein interaction domain. It has been proposed that this sub-domain of RecQ may transiently interact with multiple key proteins thus mediating DNA replication, recombination, and repair mechanisms. Evidence suggests that the WH domain binds tightly and specifically to the C-terminus of the single stranded DNA binding (SSB) protein. In addition, the C-terminal domain of the SSB protein is disordered when bound to ssDNA (Savvides et al., 2004) and it is therefore possible that this protein-protein interaction may be critical for modulating SSB function as well as perhaps regulating the enzymatic acitivity of RecQ. The goal in this collaboration (between the Keck and the Butcher laboratories) is to map the protein-protein interaction between the WH domain of RecQ helicase and a critical 10 amino acid stretch within the C-terminus of the SSB protein by NMR spectroscopy. In addition, we aim to identify the ssDNA, dsDNA, and SSB binding sites on the WH domain of the E. Coli RecQ protein.