The conserved function of the replication components extends to the clamp loader and processivity clamp as well other functions of the replisome.

The roles of RFC and PCNA are analogous to the E. coli γ clamp loader and β2 processivity unit

TLS Online TPP Program

#Id: 8622

#Unit 2. Cellular Organization

Cyclins are degraded through the action of two different E3-ligases:

1. SCF (Skp1, Cullin, and F-box proteins) 

2. APC/C or cyclosome

TLS Online TPP Program

#Id: 8623

#Unit 2. Cellular Organization

SCF and APC/C are multisubunit ubiquitin-protein ligases that belong to the RING finger family of ubiquitin-protein ligases.

TLS Online TPP Program

#Id: 8624

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8625

#Unit 2. Cellular Organization

Human SCF complexes contain: 

Three core components - Cul1 subunit, RBX1, Skp1 

and a substrate-targeting F-box protein

TLS Online TPP Program

#Id: 8626

#Unit 2. Cellular Organization

RBX1 is a RING finger–containing protein that binds the E2 ubiquitin-conjugating enzyme.

TLS Online TPP Program

#Id: 8627

#Unit 2. Cellular Organization

phosphoserine/threonine-binding F-box protein is Skp2, which uses a series of leucine-rich repeats to bind to target proteins only when they are phosphorylated.