title: Conformation of full-length Bruton tyrosine kinase (Btk) from synchrotron X-ray solution scattering.
abstract: Brutons's tyrosine kinase (Btk) is a non-receptor protein tyrosine kinase (nrPTK) essential for the development of B lymphocytes in humans and mice. Like Src and Abl PTKs, Btk contains a conserved cassette formed by SH3, SH2 and protein kinase domains, but differs from them by the presence of an N-terminal PH domain and the Tec homology region. The domain structure of Btk was analysed using X-ray synchrotron radiation scattering in solution. Low resolution shapes of the full-length protein and several deletion mutants determined ab initio from the scattering data indicated a linear arrangement of domains. This arrangement was further confirmed by rigid body modelling using known high resolution structures of individual domains. The final model of Btk displays an extended conformation with no, or little, inter-domain interactions. In agreement with these results, deletion of non-catalytic domains failed to enhance the activity of Btk. Taken together, our results indicate that, contrary to Src and Abl, Btk might not require an assembled conformation for the regulation of its activity.
authors.affiliation: European Molecular Biology Laboratory, Grenoble Outstation, 6, rue Jules Horowitz, BP181 38042 Grenoble Cedex 9, France. marquez@embl-grenoble.fr
authors.forename: José A
authors.initials: JA
authors.lastname: Márquez
authors.forename: C I Edvard
authors.initials: CI
authors.lastname: Smith
authors.forename: Maxim V
authors.initials: MV
authors.lastname: Petoukhov
authors.forename: Paola
authors.initials: P
authors.lastname: Lo Surdo
authors.forename: Pekka T
authors.initials: PT
authors.lastname: Mattsson
authors.forename: Marika
authors.initials: M
authors.lastname: Knekt
authors.forename: Anna
authors.initials: A
authors.lastname: Westlund
authors.forename: Klaus
authors.initials: K
authors.lastname: Scheffzek
authors.forename: Matti
authors.initials: M
authors.lastname: Saraste
authors.forename: Dmitri I
authors.initials: DI
authors.lastname: Svergun
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D003001:Cloning, Molecular; D006801:Humans; D008958:Models, Molecular; D011487:Protein Conformation; D011505:Protein-Tyrosine Kinases / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D017356:Synchrotrons; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D011994:Recombinant Proteins; D012996:Solutions; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human; C000625951:Btk protein, mouse