Cross-linking and mass spectrometry (XL-MS) workflows represent an increasingly popular technique for low-resolution structural studies of macromolecular complexes. Cross-linking reactions take place in the solution state, capturing contact sites between components of a complex that represent the native, functionally relevant structure. Protein-protein XL-MS protocols are widely adopted, providing precise localization of cross-linking sites to single amino acid positions within a pair of cross-linked peptides. In contrast, protein-RNA XL-MS workflows are evolving rapidly and differ in their ability to localize interaction regions within the RNA sequence. Here, we review protein-protein and protein-RNA XL-MS workflows, and discuss their applications in studies of protein-RNA complexes. The examples highlight the complementary value of XL-MS in structural studies of protein-RNA complexes, where more established high-resolution techniques might be unable to produce conclusive data.

交联和质谱 (XL-MS) 工作流程代表了一种越来越流行的大分子复合物低分辨率结构研究技术。交联反应在溶液状态下发生，捕获代表天然、功能相关结构的复合物组分之间的接触位点。蛋白质-蛋白质 XL-MS 协议被广泛采用，可将交联位点精确定位到一对交联肽内的单个氨基酸位置。相比之下，蛋白质-RNA XL-MS 工作流程发展迅速，并且它们在 RNA 序列内定位相互作用区域的能力各不相同。在这里，我们回顾了蛋白质-蛋白质和蛋白质-RNA XL-MS 工作流程，并讨论了它们在蛋白质-RNA 复合物研究中的应用。