Related Experiment Video
Updated: Sep 25, 2026

Enzymatic Modification and Flow Cytometry Assessment of Yeast Surface Displayed Proteins
Published on: May 30, 2025
Conserved hydrophobicity in the SH2-kinase linker is required for catalytic activity of Csk and CHK
Esa T Mikkola1, Mathias Bergman
1Division of Biochemistry, Department of Biosciences, P.O. Box 56, 00014 University of Helsinki, Finland. esa.t.mikkola@helsinki.fi
Abstract:
The crystal structure of full-length Csk (C-terminal Src kinase) molecules shows a hydrophobic interaction between the SH2-kinase linker residue Phe183 and the alphaC-helix of the catalytic domain. To study the possible involvement of this contact in the regulation of the activity of Csk and CHK (Csk homologous kinase), a Csk SH2-kinase linker deletion mutant, Csk Phe183 and CHK Leu223 point mutants were analyzed. It was observed that a residue with a long hydrophobic side chain in position 183 (Csk) and 223 (CHK) is required to sustain the catalytic activity of Csk and CHK. These results suggest that Csk Phe183 and CHK Leu223 stabilize the movement of the alphaC-helix of these protein tyrosine kinases.
Related Concept Videos
The JAK-STAT Signaling Pathway
Conservation of Protein Domains Over Different Proteins
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Amplifying Signals via Enzymatic Cascade
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...

