Phasing and structure of bestrophin-1: a case study in the use of heavy-atom cluster compounds with multi-subunit transmembrane proteins

Journal Article · Tue Mar 01 00:00:00 EST 2016 · Acta Crystallographica. Section D. Structural Biology

DOI:https://doi.org/10.1107/S2059798315022524· OSTI ID:1426255

Kane Dickson, Veronica

The purification and three-dimensional crystallization of membrane proteins are commonly affected by a cumulation of pathologies that are less prevalent in their soluble counterparts. This may include severe anisotropy, poor spot shape, poor to moderate-resolution diffraction, crystal twinning, translational pseudo-symmetry and poor uptake of heavy atoms for derivatization. Such challenges must be circumvented by adaptations in the approach to crystallization and/or phasing. Here, an example of a protein that exhibited all of the above-mentioned complications is presented. Bestrophin-1 is a eukaryotic calcium-activated chloride channel, the structure of which was recently determined in complex with monoclonal antibody fragments using SAD phasing with tantalum bromide clusters (Ta₆Br₁₂·Br₂). Some of the obstacles to obtaining improved diffraction and phasing for this particular channel are discussed, as well as the approach and adaptations that were key to determining the structure.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
• Sponsoring Organization: OTHER
• OSTI ID: 1426255
• Journal Information: Acta Crystallographica. Section D. Structural Biology, Vol. 72, Issue 3; ISSN 2059-7983
• Publisher: IUCr
• Country of Publication: United States
• Language: ENGLISH