Davies Roberta B, Smits Callum, Wong Andrew S W, Stock Daniela, Christie Mary, Sandin Sara, Stewart Alastair G
Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.
NTU Institute of Structural Biology, Nanyang Technological University, 636921, Singapore.
J Struct Biol. 2017 Mar;197(3):350-353. doi: 10.1016/j.jsb.2017.01.002. Epub 2017 Jan 20.
The bacterial A/V-type ATPase/synthase rotary motor couples ATP hydrolysis/synthesis with proton translocation across biological membranes. The A/V-type ATPase/synthase from Thermus thermophilus has been extensively studied both structurally and functionally for many years. Here we provide an 8.7Å resolution cryo-electron microscopy 3D reconstruction of this complex bound to single-domain antibody fragments, small monomeric antibodies containing just the variable heavy domain. Docking of known structures into the density revealed the molecular orientation of the domain antibodies, suggesting that structure determination of co-domain antibody:protein complexes could be a useful avenue for unstable or smaller proteins. Although previous studies suggested that the presence of fluoroaluminate in this complex could change the rotary state of this enzyme, we observed no gross structural rearrangements under these conditions.
细菌A/V型ATP酶/合酶旋转马达将ATP水解/合成与质子跨生物膜转运偶联起来。嗜热栖热菌的A/V型ATP酶/合酶在结构和功能方面已经被广泛研究多年。在此，我们提供了该复合物与单域抗体片段（仅包含可变重链结构域的小单体抗体）结合的8.7埃分辨率低温电子显微镜三维重建图。将已知结构对接至密度图中揭示了结构域抗体的分子取向，这表明共结构域抗体：蛋白质复合物的结构测定可能是研究不稳定或较小蛋白质的一条有用途径。尽管先前的研究表明该复合物中氟铝酸盐的存在可能会改变这种酶的旋转状态，但我们在此条件下未观察到明显的结构重排。
