F-box Domain

Domain Binding and Function

The F-box domain is a 42–48 amino acid conserved domain found at the N-terminus of F-box proteins. F-box proteins act as adaptor components of the modular E3 ubiquitin ligase SCF complex that functions in phosphorylation-mediated ubiquitination. The F-box domain mediates interaction with SKP1, which links F-box proteins to a core ubiquitin-ligase complex composed of Rbx1, cdc53/Cul1 and the E2 conjugating enzyme cdc34. The C-terminal region of F-box proteins are also composed of various modular domains that interact with target substrates, often in a phosphorylation-dependent manner.

Structure Reference

1. Schulman, B.A. et al. (2000) Nature 408(6810), 381–386.

Examples of Domain Proteins

Binding Examples

F-box Domain Proteins	Binding Partners	C-terminal Binding Partners
Cdc4 (Yeast)	Skp1, Rbx1	Sic1, CDK inhibitor
Grr1 (Yeast)	Skp1, Rbx1	Cyclin (CLN) 1,2
TrCp (Yeast)	Skp1, Rbx1	IκB, NF-κB regulator