Serine/Threonine Phosphatases and Kinases

Question 1

Phosphorylation Reaction

Answer 1

Nucleophilic attack of hydroxyl group on gamma phosphate of ATP.
Kinases bind these groups close together to facilitate reaction.

Question 2

Protein Kinase Structure

Answer 2

Alpha helix large lobes and beta sheet small lobes
Helix C: binds ATP
Glycine Loops: positions gamma phosphate
Activation loops: might need phosphorylated to perform catalysis

Question 3

Phosphorylation Residues (3)

Answer 3

Serine, Threonine, Tyrosine

Occurs at hydroxyl group

Question 4

Effects of phosphorylation

Answer 4

inhibitory or activating. Can affect gene expression.

Question 5

Structure of ATP

Answer 5

Ribose sugar with adenine base attached via glycosidic bond at 1 position. 3 phosphates attached via phosphodiester bond at 5 position. Alpha, Beta, Gamma phosphates linked via phosphoanhydride bonds.

Question 6

Classifications of Kinases (4)

Answer 6

Phosphorylated Residue: Ser/Tyr/Thr
Substrate: myosin light chain kinase
Activating stimulus: Mitogen-activated protein kinase
Phylogenic relationship (family): CAMK, AGC