Diagrams & Tables: Phosphate-handling enzymes

Class	Actions	Examples
Phosphorylases	Transfer of phosphate group from an inorganic phosphate to an acceptor (usually a sugar). Bacterial phosphorylases employ the same catalytic mechanisms as their plant and animal counterparts, but differ considerably in terms of their substrate specificity and regulation. That is, catalytic domains are highly conserved, while the regulatory sites are only poorly conserved. [s][r]	glycogen phosphorylase
Protein kinases	Transfer a phosphate group from a donor such as ATP to amino acid acceptors in proteins. Serve important roles in signal transduction.	protein kinase A, protein kinase C, protein tyrosine kinases (PTKs), cAMP-dependent protein kinase (AKAPs), MAP Kinase, receptor tyrosine kinases, (RTKs), Table RTKs, w Ca2+/calmodulin-dependent protein kinases, w Mos/Raf kinases, w Protein Kinase B, w Receptor-associated tyrosine kinases, w Histidine-specific protein kinases, w Aspartic acid/glutamic acid-specific protein kinases
Phosphatases	Remove, from amino acids, the phosphate groups attached by protein kinases. Serve important roles in signal transduction.	PP1 (α, β, γ1, γ2), PP2A, w calcineurin (PP2B), PP2C, PP4, PP5 tyrosine phosphatases (CD45)
Adenylyl (adenylate) cyclases	Convert ATP to the second-messenger cAMP plus pyrophosphate. Serve important roles in eukaryotic signal transduction.	ADCY1, ADCY2, ADCY3, ADCY4, ADCY5, ADCY6, ADCY7, ADCY8, ADCY9
Phospholipases, (phospholipases)	Hydrolyze specific ester bonds in phosphoglycerides or glycerophosphatidates, converting the phospholipids into fatty acids and other lipophilic substances. Participate in transmission of ligand-receptor induced signals from the plasma membrane to intracellular proteins, primarily protein kinase C (PKC), which is maximally active in presence of Ca²⁺ and diacylglycerol.	PLA1, PLA2, w Phospholipase A (PLA), w Phospholipase B (PLB), w Phospholipase C (PLC), Phospholipase D (PLD)
Phosphodiesterases	Catalyze the hydrolysis of phosphodiester bonds, and so degrade the cyclic nucleotides, second messengers cAMP and cGDP to 5'-nucleotide monophosphates (AMP, GMP) Important in regulation of signal transduction.	Enzymes of 10 identified phosphodiesterase families exist as homodimers with structural similarity, but differences with respect to selectivity for cyclic nucleotides, sensitivity for inhibitors and activators, physiological roles and tissue distribution.
DNA ligases	DNA ligase forms covalent phospodiester bonds between 3'-OH of one nucleotide and 5'-PO4 of another. DNA ligases are important research tools in recombinant DNA technology. 3'-phospodiesterase is important in repair of oxidative DNA damage.	DNA ligases I, II, III, IV