glycogen phosphorylase (PYGL) dimer b + 2 ATP => glycogen phosphorylase (PYGL) dimer a + 2 ADP EC Number: 2.7.11.19 Pubmed10487978 Pubmed12825073 Pubmed12930917 Pubmed13115432 Pubmed5461220 Pubmed7847371 Pubmed8896567 Reactome Database ID Release 4371588 Reactome, http://www.reactome.org ReactomeREACT_1623 The cytosolic phosphorylase kinase complex catalyzes the phosphorylation of glycogen phosphorylase (PYGL). Two forms of phosphorylase kinase complex have been described (Brushia and Walsh 1999). The one annotated here, consisting of four copies each of PHKA2 (alpha regulatory) (van den Berg et al. 1995), PHKB (beta regulatory) (Burwinkel et al. 2003a), PHKG2 (gamma catalytic) (Burwinkel et al. 2003b; Maichele et al. 2006) and CALM (calmodulin) subunits is abundant in liver and its action on the form of phosphorylase (PYGL) abundant in liver is described.<p>While initial studies of glycogen phosphorylase PGYM from rabbit muscle suggested that it is a homotetramer (Keller and Cori 1953), more recent work indicates that under physiological conditions the enzyme occurs as a homodimer (Huang and Graves 1970) and a dimeric structure for human PYGL enzyme is inferred here. has a Stoichiometric coefficient of 2 PGYL dimer b form PGYL dimer a form