Division of Liberal Arts and Sciences, Department of Chemistry, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju, 500-712, Republic of Korea,
J Biomol NMR. 2014 Feb;58(2):141-7. doi: 10.1007/s10858-014-9812-8. Epub 2014 Jan 17.
RecQ C-terminal (RQC) domain is known as the main DNA binding module of RecQ helicases such as Bloom syndrome protein (BLM) and Werner syndrome protein (WRN) that recognizes various DNA structures. Even though BLM is able to resolve various DNA structures similarly to WRN, BLM has different binding preferences for DNA substrates from WRN. In this study, we determined the solution structure of the RQC domain of human BLM. The structure shares the common winged-helix motif with other RQC domains. However, half of the N-terminal has unstructured regions (α1-α2 loop and α3 region), and the aromatic side chain on the top of the β-hairpin, which is important for DNA duplex strand separation in other RQC domains, is substituted with a negatively charged residue (D1165) followed by the polar residue (Q1166). The structurally distinctive features of the RQC domain of human BLM suggest that the DNA binding modes of the BLM RQC domain may be different from those of other RQC domains.
RecQ C 端（RQC）结构域是 RecQ 解旋酶（如布卢姆综合征蛋白（BLM）和 Werner 综合征蛋白（WRN））的主要 DNA 结合模块，可识别各种 DNA 结构。尽管 BLM 能够像 WRN 一样类似地解析各种 DNA 结构，但 BLM 对 DNA 底物的结合偏好与 WRN 不同。在这项研究中，我们确定了人 BLM 的 RQC 结构域的溶液结构。该结构与其他 RQC 结构域共享常见的翼螺旋基序。然而，N 端的一半具有无规卷曲区域（α1-α2 环和 α3 区域），并且在其他 RQC 结构域中对 DNA 双链分离很重要的β发夹顶部的芳基侧链被带负电荷的残基（D1165）取代，随后是极性残基（Q1166）。人 BLM 的 RQC 结构域的结构特征表明，BLM RQC 结构域的 DNA 结合模式可能与其他 RQC 结构域不同。
