title: Purification, crystallization and preliminary crystallographic analysis of the SH2 domain of IL-2-inducible T-cell kinase.
abstract: Proline is a unique amino acid owing to the relatively small energy difference between the cis and trans conformations of its peptide bond. The X-Pro imide bond readily undergoes cis-trans isomerization in the context of short peptides as well as some proteins. However, the direct detection of cis-trans proline isomerization in folded proteins is technically challenging. NMR spectroscopy is well suited to the direct detection of proline isomerization in folded proteins. It is less clear how well X-ray crystallography can reveal this conformational exchange event in folded proteins. Conformational heterogeneity owing to cis-trans proline isomerization in the Src homology 2 (SH2) domain of the IL-2-inducible T-cell kinase (ITK) has been extensively characterized by NMR. Using the ITK SH2 domain as a test system, an attempt was made to determine whether proline isomerization could be detected in a crystal structure of the ITK SH2 domain. As a first step towards this goal, the purification, crystallization and preliminary characterization of the ITK SH2 domain are described.
authors.affiliation: Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
authors.forename: Raji E
authors.initials: RE
authors.lastname: Joseph
authors.forename: Nathaniel D
authors.initials: ND
authors.lastname: Ginder
authors.forename: Julie A
authors.initials: JA
authors.lastname: Hoy
authors.forename: Jay C
authors.initials: JC
authors.lastname: Nix
authors.forename: Richard B
authors.initials: RB
authors.lastname: Honzatko
authors.forename: Amy H
authors.initials: AH
authors.lastname: Andreotti
mesh_terms: D000818:Animals; D003460:Crystallization; D018360:Crystallography, X-Ray; D051379:Mice; D008968:Molecular Conformation; D010455:Peptides / Q000378:metabolism; D011392:Proline / Q000737:chemistry / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000737:chemistry*; D014961:X-Ray Diffraction; D018909:src Homology Domains
chemical_list: D010455:Peptides; D011392:Proline; D011505:Protein-Tyrosine Kinases; C080813:emt protein-tyrosine kinase