GPIbβ binding to 14-3-3ζ deletion mutants is reduced compared with the interaction with full-length 14-3-3ζ. The binary protein interactions along with the further controls shown in Fig 2 and 3 additional positive and 4 negative control transformations not shown were studied, and quantitative β-galactosidase assays were performed. Deletion mutant activity was reduced 51% to 59% v full-length 14-3-3. Data bars represent the mean ± SE of 5 separate experiments using analysis of 37 independent colonies with 3 spectrophotometric readings per colony at different concentrations.