De Novo Phasing with X-Ray Laser Reveals Mosquito Larvicide Binab Structure.Colletier, J., Sawaya, M.R., Gingery, M., Rodriguez, J.A., Cascio, D., Brewster, A.S., Michels-Clark, T., Hice, R.H., Coquelle, N., Boutet, S., Williams, G.J., Messerschmidt, M., Deponte, D.P., Sierra, R.G., Laksmono, H., Koglin, J.E., Hunter, M.S., Park, H., Uervirojnangkoorn, M., Bideshi, D.K., Brunger, A.T., Federici, B.A., Sauter, N.K., Eisenberg, D.S.
(2016) Nature 539: 43
- PubMed: 27680699
- DOI: 10.1038/nature19825
- Primary Citation of Related Structures:
- PubMed Abstract:
BinAB is a naturally occurring paracrystalline larvicide distributed worldwide to combat the devastating diseases borne by mosquitoes. These crystals are composed of homologous molecules, BinA and BinB, which play distinct roles in the multi-step int ...
BinAB is a naturally occurring paracrystalline larvicide distributed worldwide to combat the devastating diseases borne by mosquitoes. These crystals are composed of homologous molecules, BinA and BinB, which play distinct roles in the multi-step intoxication process, transforming from harmless, robust crystals, to soluble protoxin heterodimers, to internalized mature toxin, and finally to toxic oligomeric pores. The small size of the crystals-50 unit cells per edge, on average-has impeded structural characterization by conventional means. Here we report the structure of Lysinibacillus sphaericus BinAB solved de novo by serial-femtosecond crystallography at an X-ray free-electron laser. The structure reveals tyrosine- and carboxylate-mediated contacts acting as pH switches to release soluble protoxin in the alkaline larval midgut. An enormous heterodimeric interface appears to be responsible for anchoring BinA to receptor-bound BinB for co-internalization. Remarkably, this interface is largely composed of propeptides, suggesting that proteolytic maturation would trigger dissociation of the heterodimer and progression to pore formation.
UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California, Los Angeles, California 90095-1570, USA.,Department of Entomology and Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, California 92521, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Biological Sciences, California Baptist University, Riverside, California 92504, USA.,Molecular and Cellular Physiology, and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA.,Howard Hughes Medical Institute, University of California, Los Angeles, California 90095-1570, USA.,Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France.,Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.