C2 domain found in protein kinase C (Pkc1p) in Saccharomyces cerevisiae
This family is named after the protein kinase C in Saccharomyces cerevisiae, Pkc1p. Protein kinase C is a member of a family of Ser/Thr phosphotransferases that are involved in many cellular signaling pathways. PKC has two antiparallel coiled-coiled regions (ACC finger domain) (AKA PKC homology region 1 (HR1)/ Rho binding domain) upstream of the C2 domain and two C1 domains downstream. The C2 domain was first identified in PKC. C2 domains fold into an 8-standed beta-sandwich that can adopt 2 structural arrangements: Type I and Type II, distinguished by a circular permutation involving their N- and C-terminal beta strands. Many C2 domains, like those of PKC, are Ca2+-dependent membrane-targeting modules that bind a wide variety of substances including bind phospholipids, inositol polyphosphates, and intracellular proteins. Most C2 domain proteins are either signal transduction enzymes that contain a single C2 domain, such as protein kinase C, or membrane trafficking proteins which contain at least two C2 domains, such as synaptotagmin 1. However, there are a few exceptions to this including RIM isoforms and some splice variants of piccolo/aczonin and intersectin which only have a single C2 domain. C2 domains with a calcium binding region have negatively charged residues, primarily aspartates, that serve as ligands for calcium ions.
Jiyao W et al.(2023). "The conserved domain database in 2023.",