Protein
DDK kinase regulatory subunit DBF4
Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
Function
Regulatory subunit of the CDC7-DBF4 kinase, also called DBF4-dependent kinase (DDK), which is involved in cell cycle regulation of premitotic and premeiotic chromosome replication and in chromosome segregation. DDK plays an essential role in initiating DNA replication at replication origins by phosphorylating the MCM2 and MCM4 subunits of the MCM2-7 helicase complex. DBF4 recruits the catalytic subunit CDC7 to MCM2 and to origins of replication. DDK has also postreplicative functions in meiosis. DDK phosphorylates the meiosis-specific double-strand break protein MER2 for initiation of meiotic recombination. Interacts with CDC5 during meiosis to promote double-strand breaks and monopolar spindle orientation. Inhibits CDC5 activity during mitosis through direct binding to its PBD.
Sequence
MVSPTKMIIRSPLKETDTNLKHNNGIAASTTAAGHLNVFSNDNNCNNNNTTESFPKKRSLERLELQQQQHLHEKKRARIERARSIEGAVQVSKGTGLKNVEPRVTPKELLEWQTNWKKIMKRDSRIYFDITDDVEMNTYNKSKMDKRRDLLKRGFLTLGAQITQFFDTTVTIVITRRSVENIYLLKDTDILSRAKKNYMKVWSYEKAARFLKNLDVDLDHLSKTKSASLAAPTLSNLLHNEKLYGPTDRDPRTKRDDIHYFKYPHVYLYDLWQTWAPIITLEWKPQELTNLDELPYPILKIGSFGRCPFIGDRNYDESSYKRVVKRYSRDKANKKYALQLRALFQYHADTLLNTSSVNDQTKNLIFIPHTCNDSTKSFKKWMQEKAKNFEKTELKKTDDSAVQDVRNEHADQTDEKNSILLNETETKEPPLKEEKENKQSIAEESNKYPQRKELAATPKLNHPVLATFARQETEEVPDDLCTLKTKSRQAFEIKASGAHQSNDVATSFGNGLGPTRASVMSKNMKSLSRLMVDRKLGVKQTNGNNKNYTATIATTAETSKENRHRLDFNALKKDEAPSKETGKDSAVHLETNRKPQNFPKVATKSVSADSKVHNDIKITTTESPTASKKSTSTNVTLHFNAQTAQTAQPVKKETVKNSGYCENCRVKYESLEQHIVSEKHLSFAENDLNFEAIDSLIENLRFQI