The following text describes a protein:
Function:
Serine/threonine-protein kinase that acts as a molecular sensor for DNA damage. Involved in DNA nonhomologous end joining (NHEJ) required for double-strand break (DSB) repair and V(D)J recombination. Must be bound to DNA to express its catalytic properties. Promotes processing of hairpin DNA structures in V(D)J recombination by activation of the hairpin endonuclease artemis (DCLRE1C). Recruited by XRCC5 and XRCC6 to DNA ends and is required to (1) protect and align broken ends of DNA, thereby preventing their degradation, (2) and sequester the DSB for repair by NHEJ. Acts as a scaffold protein to aid the localization of DNA repair proteins to the site of damage. The assembly of the DNA-PK complex at DNA ends is also required for the NHEJ ligation step. Found at the ends of chromosomes, suggesting a further role in the maintenance of telomeric stability and the prevention of chromosomal end fusion. As part of the DNA-PK complex, involved in the early steps of ribosome assembly by promoting the processing of precursor rRNA into mature 18S rRNA in the small-subunit processome (By similarity). Recognizes the substrate consensus sequence [ST]-Q. Phosphorylates 'Ser-139' of histone variant H2AX, thereby regulating DNA damage response mechanism (By similarity).
Subcellular Localization:
Nucleus. Nucleus, nucleolus.
Sequence:
MAGGVQECLQELHGCLQPGDAMRGYGLLRGLGEACLTCLAGGALALHVSLVFAPERGLLAFVCRSLGVEEFRECREEALKFLCVFLERIGERAHPYACSLKQTCISVYTKERAAKCKIPALELLIKLLQSLRRSCLMEEMKVGEIFNKFYGELAVRSKISDTVLEKIYELLGVLGEVHPADMINNSEKLFRAYLGELKTQMTSATRVPKLPIVAGCLRGLTALMYNFTKSVDEDAQTSKEIFDFAVKAIRPQVDQKRYAVHLAGLQLFSWHAAQFGTLLLDSYVMLFETMCRWCGHTNQELKKAGHNALDSFLKQMSLMVAKDAELHKSKLKFFMEQFYGIIRRMDSSNKELSIAIRGYGLFAAPCKAMHPADVDAMYIELLQRCKQMYLTEAETIDDHLYQLPSFLQSIASVIFHLDTIPEVYTPVLEHLVVLQINSFPRYSEKMQLVCCRSIIKVFLALSIKGPVLWNFISTVVHQGLIRVFSKPMKFSKDVFGKETSGSEEFPESGEVDTARWKVPTYKDYLYLFRSLLSCDTMKESIFEEENFLTGNSPLQSLNRLLYDELIKSILKIIEKLDLTVQKLNVHEQDENETDSAFIGPTSDPASNLQPKKPTDFIAFINLVEFCRDILPDKHVEYFQPWVYSFGYELIIHSTRLPLISGFYKLLSVTMKIAKKIKYFEGVGPKSLRKATEDPEKSSCFALFAKFGKEVTAKMKQYKDELLASCLNFLLSLPHDIVMLDIKAYIPALQNAFKLGLSCTPMADLGLDALEDWSAHIPRHIMQPYYKDVLPLLDGYLKNSATTVEPQNNWEVRKLSRAAQKGFNKIVIQRLRKAKTSSLDDNPSLEAVRTRVARLLGSLGGQINHNLITATSAEEMMKKCVSWDTKNHLSFAVPFADMKPVIYLDVFLPRVTDLALSASDRQTKIAACELLHSIVAYMLGKASQMPERQQGPPPMHQLYKRIFPVLLRLACDVDQVTRQLYEPLVMQLIHWFTNNKKFESQDTVTFLEAILSGIVDPVDSTLRDFCGQCVREFLKWSIKQTTPKQQEKSPANTKSLFKRLYSLALHPSAFKRLGAALAFNSIYREFREENSLVEQFVFEALVVFLESLALTHTDEKSLGTTQQCCDAINHLKRIIKHKAPALNKEGKRRVPRGFPATKSVCLQDVVMWLLVQCGRPQTECRHKAMELFYEFVPLLPGNNSPSSWLADVLKKRDVSFLINKFEGGGSDAKSPSGILSQPTLRDMQEPFSLLTVMRWMDMFLAALDCYNTFFELRMIKPHEILGVNERSSFLEAVDFFLETIALHDIHAAEQCFDCRSRGNIFSPQEREVYNYSKCTIIVRIMEFVTMILEICQQDFWKLLEKELLNANFIELLVMTVCDPSHIGFNTADVQVMKNLPDISVRLLKALMKSPYKEYLQLCLKKRITPQSFEDLCSVDLFNSDARFDQVRFSAVLSACKQLQKSGLLHSVLHSQDERPHPSIGSKLLSVVYKSIAPGSERSSLPAVDISSKRLADRLLQLAFAIDDQCEELVSLLLNTVVLSVPLSKASERNFVDFSHGQYFYSLFSDTINQQLLKNLDVIVIHLMESSVSNPQMVGSILNGMLDQSFRERTIRKQQGVKLVTAVLRNWKRLDSWWAKDSSPESKMAVLTLLAKVLQIDSSVSFNTSHEAFTAVFDTYTSLLTDQNLGLNLKGHAVIILPFFTNLSGEKLHDLKNALDQLVAFNFPMSSDEFPKGTLKHNNYVDCTKKFLDALELSQSPMLLQLMTEVLCRDHRHSMEDLFQASFKRISRRSSTDKQVVLLDTVHKMFQNEDLLSNIVRQAFVDRSLLTLMSHCSLDALREFFCKIIVQAMDTLNSRFTKSNECVFDTQITKKMGYYKMLEVMYIRLSKDDVHSKDSKINQAYRGSVSVEGNELTKALIKLCYDAFTENMAGENQLLEKRRQYHCAAYNCAIAVISCVFTESKFYQGFLFTEKSEKNLLIFENLIDLKRQYVFPVEIEVPLERKKRYIAIRKEAREAWNDGQDEPKYLASASYMMDSSLSEEMSQFDFSTGVQGFSYSSQDVTASSAHFRRKETSEYMVLNDEMELEMDELNQHECMAPLTTLIKHMQRNQITPKVEEGVIPVDLPLWMKFLHSKLGNPSVPLNIRLFIAKLIVNTEDVFRPYAKQWLGPMLQLVVSGDNGGEGIHYMVVEIAVTVLSWTSVTTPKGNIKDEILANRLLEFLMKNAFHQKRAVFRHNLEIIKTVIECWKNCLSIPYSLIFEKFSSGDPDTKDNSVGIQLLGIVLANNLPPFDLKCEIDRVRYFQALVSNMGLLRYKEVYAAAAEVLGLALQYIAERQNILEDPVYDCVIKQLKRHQNTQQDKFIICLNKVVKNFPPLADRFMNAVFFLIPKLHGVMKNYCLEVIMCRAEEIPDLYLQLKSKDFIQIMKHRDDERQRVCLDIIYKMLSTLKPPELKELLPGVTGFISHPSVICRQRMYDILMWIYDNYSDPESQADGDSQEVLSLAKEILLQGLIDENAELQLIVRNFWSDETRLPANILDRMLMLLNSLYSAKIETQYLSLITNFLLEMTSKSPDYSRKIFEHPLSECKFHDFVIDSSWRYRSTMLTPMFVETQASQSTNRNSSQERSLSISGSVGGRVRATQRQYEFTPTQNVSGRSSFNWLTGNSIDTLAEYTVPSSSESLSSSMLLVNKRSEKFKQAAFKPVGPDFGKKRLSLPGDKVDSKTKGIDERAEILRLRRRFLKDQEKVSLIYARKGVAEQKREKEMKSELKMKFDGQVTLYRSYRVGDLPDIQIEHCSLIAPLQGLAQKDPTFAKQLFSSLFGGIFCEVKKSKIPSEKKAIIQKLLKDFNHFLSTSVSYFPPFIACIQEISYKHRELLELDSANVSTSCLASLQQPVGILLLEHALMALSPAEEPPSKRMRGRTELPPDVVKWLELAKLYRSLGDYDVLRGIFSGKIGTKDITQQALLAEARSDYAEAAKCYDEALSKEDWEDGEPTEAEKDFWELASLECYDHLTEWKSLEYCATVNIDSGKPPDLNKTWSDPFYQETYLPYIIRSKLKLLLNGENDQTLLTFIDEAMKTEQKKALIEMHYSQELSLLYILQDDFDRAKYYIGNGIQIFMQSYSSIDTLLYQSRMSKLQSVQALTEIQDFINFMTKTSNIASQAKSLKRLLRTWTSRYPDAKMDPMNIWDDIITNRCFFLDKLQEKFLCDKANDSMEVDEESSVGDQMEVDQQDEDIHSMIRSCKFNMKLKMIESARKQNSFSIAKKLLKGLRREAKTREDWLVRWNYAYCRFVHSCSQSQSCPERVLSVLKTISLLEDTKSDYLNKNIMAFRNQNLLLGTTYHIMANALSQDPKCCEQIEEEKTGKILELSGESSESPEKILAGLNKRAFQCFSSAARKSEEEVQSLSMEHVDVKGVIDAYMTLVGFCDQHLRKEEEGSLEINAADLQLFPAIVVEKMIKALKLNSREARLRFPRLLQIIERYPAETLGLVTRELPSVPCWQFIGWISQMMALLDKDEAVAVQHTVEEIVDTYPQAIIYPFTISSESYCFKDTAAGCRNKEFVASIKNKLDRGGVVQDFIHALEQLSNPVMLFKDWVADVRNELVKTQRNKIILKEMYEGMYKNLGDVKAPGLGWLRKRFVQAFGKDFDSHFGKGGSKLLDMKISDFNEITTALLTKMNKTHKEPGNLKECSPWMSEFRAEFLRNELEVPGQYDGKGKPLPEYHVKISGFDERIMVLESLRKPKRITIRGSDEQEHPFLVKGGEDLRQDQRIEQLFDVMNIVLSRDAACSQRNMQLKTYQVIPMTTRLGLIKWLENTCTLKEFLRNSMTEEEDANYNSLKGPRAAYSDWLSKMGGKAQGLSRYNAMYKNASRTETVIAFKSRESSVPEDLLRRAFVKMSTSPEAFLALRSHFVSSHALMCVSHWILGIGDRHLSNFMINKETGGMVGIDFGHAFGSATQFLPVPELMPFRLTRQFVNLMMPVKEWGLIYSVMVHALRAYRADPDLLISTMDVFVKEPSLDWKNFEQRQLKKGGTWIKEINTAEVNWYPLQKVSYVKRKLTGANPARITCDELRLGYEKLPFYNDFAAVARGSADHNIRAKEPEDRLSEETQVRCLIDQATDPNLLGRVWEGWEPWM