Fig. 6: Flexibility and multiple auto-inhibitory states of talin.
a Coulomb potential map of our partial 3.39 Å resolution talin structure, talin3.39, with its distinct R13 position showing the conventional R13 location with no map coverage. b Although the map in the R13 region is of insufficient quality to assign amino acids unambiguously, the five α-helices can be placed with reasonable certainty. c In contrast, the Coulomb potential map is unambiguous for the remainder of talin3.39 (F2, R1-12). d Our structures show that the talin core (F3, R1-R12; gray) is rigid while the amino- (F0, blue; F1, green, F2, yellow) and carboxy-terminal domains (R12, orange; R13, red) are dynamic. Notably, while the integrin binding site on F3 is inaccessible, the F-actin binding domain, R13, can bind to F-actin. e Multiple states of inactive talin (i, talin5.5; ii, talin3.4; iii, talin3.7; and iv, talin2.7) suggest a loose attachment of the amino- (F0–F2) and carboxy-terminal (R12–R13) domains without affecting the core (F3, R1-R11) that defines the closed state of talin.
