"The F-box is a protein motif of approximately 50 amino acids that functions as a site of protein-protein interaction."
"The F-box of Elongin A binds Elongin C (El C). The association of Elongins B and C with A increases Elongin A transcriptional activity."
"SCF complexes generally recognize substrates after they are phosphorylated on specific epitopes . Phosphorylation is one of the major mechanisms used by cells to rapidly transduce signals. SCF complexes are therefore ideal for dynamic processes that require an abrupt change to be made irreversible (at least in the short term) via the degradation of key proteins. Examples of such processes are cell-cycle phase transitions - during which the cell-cycle regulators that were required for the previous phase are degraded as the cell enters the new phase - and shifts in transcription that last for a longer time period than otherwise because a transcriptional inhibitor is degraded. There is a wide variety of SCF targets that include cell-cycle regulators, for example, G1-phase cyclins, cyclin-dependent kinase inhibitors, DNA replication factors, and transcription factors that promote cell-cycle progression, as well as non-cell-cycle functions, such as a cytoskeletal regulator, cell-surface receptors, transcription-factor inhibitors, and non-cell-cycle transcription factors (Table 2)."
"Second, Elongin A, the transcriptionally active subunit of the Elongin (SIII) complex - which facilitates transcription elongation by RNA polymerase II  - is an F-box protein (Figure 2c). Elongin A was isolated by virtue of its ability to increase the catalytic rate of transcript elongation by RNA polymerase II in vitro . Binding of the other components of the complex, Elongin B and C, increases the specific activity of Elongin A. The F-box motif of Elongin A is in the smallest region shown to be sufficient for Elongin A to bind Elongin C in both yeast and humans [17,18]. Elongin C has homology to Skp1; the F-box-Elongin C interaction may therefore be evolutionarily conserved."
- Edward T Kipreos and Michele Pagano (10 November 2000). "The F-box protein family". Genome Biology 1 (5): 3002. doi:10.1186/gb-2000-1-5-reviews3002. https://genomebiology.biomedcentral.com/articles/10.1186/gb-2000-1-5-reviews3002. Retrieved 2017-02-13.