The replisome exists only as a protein complex associated with the particular structure that DNA takes at the replication fork.

TLS Online TPP Program

#Id: 8865

#Unit 2. Cellular Organization

The phosphorylation state of T14 and Y15 is controlled by a dual-specificity protein kinase known as Wee1 and a pair of dual-specificity phosphatases, Cdc25B and Cdc25C (Threonine 14 is not phosphorylated in S. pombe CDK1)

TLS Online TPP Program

#Id: 8866

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8867

#Unit 2. Cellular Organization

Cdc25B is act as a starter phosphatase that initiates CDK1 activation

Cdc25C is the workhorse phosphatase that activates the vast majority of cyclin-CDK1 complexes

TLS Online TPP Program

#Id: 8868

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8869

#Unit 2. Cellular Organization

Yeast cells with a defective wee1+ gene activate mitotic CDKs prematurely and premature entry into mitosis (smaller than normal cells

TLS Online TPP Program

#Id: 8870

#Unit 2. Cellular Organization

Fission yeast cells carrying a CDK1 mutation in which the tyrosine-15 residue is replaced by phenylalanine

show the same premature mitotic CDK activation and entry into mitosis.