title: Continuous and pulsed hydrogen-deuterium exchange and mass spectrometry characterize CsgE oligomerization.
abstract: We report the use of hydrogen-deuterium amide exchange coupled to mass spectrometry (HDX-MS) to study the interfaces of and conformational changes accompanying CsgE oligomerization. This protein plays an important role in enteric bacteria biofilm formation. Biofilms provide protection for enteric bacteria from environmental extremes and raise concerns about controlling bacteria and infectious disease. Their proteinaceous components, called curli, are extracellular functional amyloids that initiate surface contact and biofilm formation. The highly regulated curli biogenesis involves a major subunit, CsgA, a minor subunit CsgB, and a series of other accessory proteins. CsgE, possibly functioning as oligomer, is a chaperonin-like protein that delivers CsgA to an outer-membrane bound oligomeric CsgG complex. No higher-order structure, or interfaces and dynamics of its oligomerization, however, are known. In this work, we determined regions involved in CsgE self-association by continuous HDX, and, on the basis of that, prepared a double mutant W48A/F79A, derived from interface alanine scan, and verified that it exists as monomer. Using pulsed HDX and MS, we suggest there is a structural rearrangement occurring during the oligomerization of CsgE.
authors.affiliation: Department of Chemistry, Washington University , St. Louis, Missouri 63130, United States.
authors.forename: Hanliu
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine , St. Louis, Missouri 63110, United States.
authors.forename: Qin
authors.initials: Q
authors.lastname: Shu
authors.affiliation: Department of Chemistry, Washington University , St. Louis, Missouri 63130, United States.
authors.forename: Don L
authors.initials: DL
authors.lastname: Rempel
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine , St. Louis, Missouri 63110, United States.
authors.forename: Carl
authors.initials: C
authors.lastname: Frieden
authors.affiliation: Department of Chemistry, Washington University , St. Louis, Missouri 63130, United States.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Gross
mesh_terms: D018441:Biofilms / Q000254:growth & development; D041961:Deuterium Exchange Measurement / Q000379:methods; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D013058:Mass Spectrometry / Q000379:methods; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011489:Protein Denaturation; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: C561979:CsgE protein, E coli; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D011994:Recombinant Proteins