Gene Structure

The genes that code for many proteins are broken into pieces. These pieces—the exons—are separated by stretches of noncoding DNA—the introns

TLS Online TPP Program

#Id: 8616

#Section 3: Genetics, Cellular and Molecular Biology

Phosphorylation of T14 and Y15 in this G-loop

introduces negative charge that electrostatically interferes with the binding of ATP in the catalytic pocket.

TLS Online TPP Program

#Id: 8617

#Section 3: Genetics, Cellular and Molecular Biology

Wee1 kinase Inhibits CDKs in all organisms

TLS Online TPP Program

#Id: 8618

#Section 3: Genetics, Cellular and Molecular Biology

Cdc25 phosphatase Activates CDKs in fission yeast

TLS Online TPP Program

#Id: 8619

#Section 3: Genetics, Cellular and Molecular Biology

INK4s

bind to CDK4 and CDK6 monomers, blocking their interaction with cyclin D

TLS Online TPP Program

#Id: 8620

#Section 3: Genetics, Cellular and Molecular Biology

A second class of CKIs found in metazoan cells is the Cip/Kip family of CKIs, consists of three proteins—p21CIP, p27KIP1, and p57KIP2. 

TLS Online TPP Program

#Id: 8621

#Section 3: Genetics, Cellular and Molecular Biology

The Cip/Kip family members bind to cyclin-bound CDKs and block the activity of cyclin D-, E-, A-, and B-containing complexes.