Catalytic domain of Male germ cell-Associated Kinase-like Serine/Threonine Kinases
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily is composed of human MAK and MAK-related kinase (MRK), Saccharomyces cerevisiae Ime2p, Schizosaccharomyces pombe Mei4-dependent protein 3 (Mde3) and Pit1, Caenorhabditis elegans dyf-5, Arabidopsis thaliana MHK, and similar proteins. These proteins play important roles during meiosis. MAK is highly expressed in testicular cells specifically in the meiotic phase, but is not essential for spermatogenesis and fertility. It functions as a coactivator of the androgen receptor in prostate cells. MRK, also called Intestinal Cell Kinase (ICK), is expressed ubiquitously, with highest expression in the ovary and uterus. A missense mutation in MRK causes endocrine-cerebro-osteodysplasia, suggesting that this protein plays an important role in the development of many organs. MAK and MRK may be involved in regulating cell cycle and cell fate. Ime2p is a meiosis-specific kinase that is important during meiotic initiation and during the later stages of meiosis. Mde3 functions downstream of the transcription factor Mei-4 which is essential for meiotic prophase I. The MAK-like subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.
Comment:includes ATP binding and substrate binding sites
Comment:based on the structure of human CDK2 bound with ATP and substrate peptide, and on the structures of other CDKs or MAPKs, bound with ATP or ATP analogs
Jiyao W et al.(2023). "The conserved domain database in 2023.",