an enzyme that can transfer a phosphate group from a donor molecule (usually ATP ) to an amino acid residue of a protein
an enzyme which adds a phosphate group to a protein, which has the effect of activating or changing the effects of that protein
a protein which transfers the terminal phosphate group from ATP onto another protein
An enzyme that phosphorylates specific amino acid residues on specific target proteins. One major class of protein kinases phosphorylates tyrosines, and the other phosphorylates serines and threonines on target proteins.
A protein kinase is a kinase enzyme that modifies other proteins by chemically adding phosphate groups to them (phosphorylation). This usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins. Up to 30% of all proteins may be modified by kinase activity, and kinases are known to regulate the majority of cellular pathways, especially those involved in signal transduction, the transmission of signals within the cell.
