Switch #: SWTI000305

Switch type: Pre-assembly

Switch subtype: Composite binding site formation

Description:
Binding of Fibronectin (Fn1) to integrin receptors depends on pre-assembly of Integrin alpha-5 (Itga5)-Integrin beta-1 (Itgb1) heterodimers, since association of the integrin alpha and beta subunits results in the formation of a composite binding site for the RGD motif in the ligand.

Participants:
(1) Integrin alpha-5 (Itga5)
(2) Integrin beta-1 (Itgb1)
(3) Fibronectin (Fn1)

This is a sequential switch. The interactions in this switch take place in a defined order. The order is defined by numbers to the left of each interaction. More than one interaction can occur in each step, these interactions occur independently but are necessary for future step

1Interaction #1 Itga5 - Itgb1

Interfaces
(1) FG-GAP repeat in Integrin alpha-5 (Itga5)
(2) Integrin, beta chain _(34-464) in Integrin beta-1 (Itgb1)

2Interaction #2 Fn1 - Interaction #1 Itga5 - Itgb1

Requires Interaction #1 Itga5 - Itgb1

Interfaces
(3) LIG_RGD motif (₁₆₁₄RGD₁₆₁₆) in Fibronectin (Fn1)
(4) Interaction #1 Itga5 - Itgb1

(1) Solution structure and dynamics of linked cell attachment modules of mouse fibronectin containing the RGD and synergy regions: comparison with the human fibronectin crystal structure.
Copié et al. J. Mol. Biol. (1998)