Final Answer:
E3 ligases form complexes with substrate recognition adapters such as F-box proteins (SCF complexes), SOCS box proteins (SOCS complexes), DCAF proteins (Cul4-based complexes), and BTB domain-containing proteins (Cul3-based complexes), facilitating targeted ubiquitination and protein degradation.
Step-by-step explanation:
E3 ligases, which play a crucial role in the ubiquitin-proteasome system, often form complexes with substrate recognition adapters to target specific proteins for ubiquitination. Four examples of substrate recognition adapters associated with E3 ligases are:
F-box proteins: Associated with Skp1-Cullin1-F-box protein (SCF) E3 ligase complexes.SOCS box proteins:Found in suppressor of cytokine signaling (SOCS) E3 ligase complexes.DCAF (DDB1-CUL4-associated factors):*Associated with Cullin4-based E3 ligase complexes.BTB domain-containing proteins:Form complexes with Cul3-based E3 ligases.
These adapters help E3 ligases recognize specific substrates, facilitating the transfer of ubiquitin molecules onto target proteins for subsequent degradation by the proteasome.