Open AccessPurification, crystallization and preliminary crystallographic analysis of the SH2 domain of IL‐2‐inducible T‐cell kinase
Author(s) -
Joseph Raji E.,
Ginder Nathaniel D.,
Hoy Julie A.,
Nix Jay C.,
Honzatko Richard B.,
Andreotti Amy H.
Publication year - 2011
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309110052346
Subject(s) - isomerization , proline , chemistry , crystallization , sh2 domain , crystallography , nuclear magnetic resonance spectroscopy , amino acid , stereochemistry , kinase , proto oncogene tyrosine protein kinase src , biochemistry , catalysis , organic chemistry
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.