title: Cryo-EM analysis of a domain antibody bound rotary ATPase complex.
abstract: 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.
authors.affiliation: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.
authors.forename: Roberta B
authors.initials: RB
authors.lastname: Davies
authors.affiliation: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.
authors.forename: Callum
authors.initials: C
authors.lastname: Smits
authors.affiliation: NTU Institute of Structural Biology, Nanyang Technological University, 636921, Singapore.
authors.forename: Andrew S W
authors.initials: ASW
authors.lastname: Wong
authors.affiliation: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Daniela
authors.initials: D
authors.lastname: Stock
authors.affiliation: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Mary
authors.initials: M
authors.lastname: Christie
authors.affiliation: NTU Institute of Structural Biology, Nanyang Technological University, 636921, Singapore; School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
authors.forename: Sara
authors.initials: S
authors.lastname: Sandin
authors.affiliation: Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia. Electronic address: a.stewart@victorchang.edu.au.
authors.forename: Alastair G
authors.initials: AG
authors.lastname: Stewart
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000906:Antibodies / Q000378:metabolism*; D020285:Cryoelectron Microscopy / Q000379:methods*; D008565:Membrane Proteins / Q000378:metabolism; D017433:Protein Structure, Secondary; D016963:Thermus thermophilus / Q000201:enzymology
chemical_list: D000906:Antibodies; D008565:Membrane Proteins; D000251:Adenosine Triphosphatases
keywords: ATPase; Antibodies; Cryo-EM; Membrane protein