Fig. S3.

The ¹⁵N-labeled CD3ε_CD NMR signals in response to Lck_UD+SH3 titration. (A) HSQC spectra of ¹⁵N-labeled CD3ε_CD were recorded under the titration of unlabeled Lck_UD+SH3. The molar ratio of Lck/CD3ε was 0 to 10. (B) Representative residues from BRS, PRS, and ITAM. (C) A bar graph showing the resonance changes of CD3ε_CD residues caused by Lck titration. Some residues were left blank either because we were unable to detect them (such as prolines), or they were unassigned, or due to peak overlapping. The residues with peak overlapping are indicated by “O” symbols. Asterisks indicate peak broadening caused by the Lck titration.