Identification of mutants that disrupt the head-tail interaction. A–C, weighted shift map obtained from the 1H,15N HSQC spectra of talin 1655–1822, or mutants thereof, on the addition of talin F3. A, wild-type (WT) talin 1655–1822. B, E1770A talin 1655–1822. C, T1767E talin 1655–1822. D, dissociation constants for the binding of wild-type talin 1655–1822 and various mutants thereof to F3. E, dissociation constants for the binding of wild-type talin 1655–1822 to various F3 FERM subdomain mutants (obtained from analysis of the chemical shift changes of residues 319, 324, 326, 352, 359, 366, 373, and 378 in the 1H,15N HSQC spectra of F3, or mutants thereof, on the addition of talin 1655–1822).