Tyrosine kinase

There are over 100 3D structures of tyrosine kinases available at the Protein Data Bank. An example is PDB 1IRK (http://www.rcsb.org/pdb/cgi/explore.cgi?pid=232131034361062&page=60&pdbId=1IRK), the crystal structure of the tyrosine kinase domain of the human insulin receptor. The first non-receptor tyrosine kinase identified was the v-Src oncogenic protein. Most animal cells contain one or more members of the Src family of tyrosine kinases. A chicken sarcoma virus was found to carry mutated version of the normal cellular Src gene. The mutated v-src gene has lost the normal built-in inhibion of enzyme activity that is characteristic of cellular SRC (c-src) genes. SRC family members have been found to regulate many cellular processes. For example, the T-cell antigen receptor leads to intracellular signalling by activation of Lck and Fyn, two proteins that are structurally similar to Src.