cd05066: PTKc_EphR_A (this model, PSSM-Id:173639 is obsolete and has been replaced by 270651)
Catalytic domain of the Protein Tyrosine Kinases, Class EphA Ephrin Receptors
Protein Tyrosine Kinase (PTK) family; Ephrin Receptor (EphR) subfamily; most class EphA receptors including EphA3, EphA4, EphA5, and EphA7, but excluding EphA1, EphA2 and EphA10; catalytic (c) domain. The PTKc family is part of a larger superfamily that includes the catalytic domains of other kinases such as protein serine/threonine kinases, RIO kinases, and phosphoinositide 3-kinase (PI3K). PTKs catalyze the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. EphRs comprise the largest subfamily of receptor tyr kinases (RTKs). In general, class EphA receptors bind GPI-anchored ephrin-A ligands. There are ten vertebrate EphA receptors (EphA1-10), which display promiscuous interactions with six ephrin-A ligands. One exception is EphA4, which also binds ephrins-B2/B3. EphRs contain an ephrin-binding domain and two fibronectin repeats extracellularly, a transmembrane segment, and a cytoplasmic tyr kinase domain. Binding of the ephrin ligand to EphR requires cell-cell contact since both are anchored to the plasma membrane. The resulting downstream signals occur bidirectionally in both EphR-expressing cells (forward signaling) and ephrin-expressing cells (reverse signaling). Ephrin/EphR interaction mainly results in cell-cell repulsion or adhesion, making it important in neural development and plasticity, cell morphogenesis, cell-fate determination, embryonic development, tissue patterning, and angiogenesis. EphARs and ephrin-A ligands are expressed in multiple areas of the developing brain, especially in the retina and tectum. They are part of a system controlling retinotectal mapping.
Comment:Based on the structures of other PTK family members bound to substrate peptides and ATP analogs including, the structures of human EphA2 receptor bound with an ATP analog and mouse EphB2 receptor tyr kinase bound with ADP, (1MQB_B, 2HEN_A respectively).