By maintaining the unbound DNA in a relaxed state, topoisomerases facilitate the binding of histones to the DNA and the formation of additional nucleosomes.

Importantly, the overall effect on the plasmid is that the linking number is decreased as more nucleosomes are assembled

TLS Online TPP Program

#Id: 8602

#Unit 2. Cellular Organization

cyclin-CDK complexes preferentially phosphorylate

serine and threonine residues when they are found within the consensus sequence:

[S/T]PX[R/K]K 

TLS Online TPP Program

#Id: 8603

#Unit 2. Cellular Organization

G1 Cyclin–CDKs

In human - cyclin D-CDK 4 

cyclin D-CDK 6

In budding yeast - CIn 3-Cdc 28 

TLS Online TPP Program

#Id: 8604

#Unit 2. Cellular Organization

G1/S Cyclin–CDKs

In human - cyclin E-CDK 2 

In budding yeast - CIn 1/2-Cdc 28

TLS Online TPP Program

#Id: 8605

#Unit 2. Cellular Organization

S phase Cyclin–CDKs

In human - cyclin A-CDK 2 

In budding yeast - CIb 5/6-Cdc 28

TLS Online TPP Program

#Id: 8606

#Unit 2. Cellular Organization

M phase Cyclin–CDKs

In human - cyclin A-CDK 1

cyclin B-CDK 1

In budding yeast - CIb 1/2/3/4-Cdc 28

TLS Online TPP Program

#Id: 8607

#Unit 2. Cellular Organization

Cdk1 

=Cdc2 (vertebrates and fission yeast)

= Cdc28  (budding yeast)