General transcription and DNA repair factor IIH helicase subunit XPB (TFIIH subunit XPB) (EC 3.6.4.12) (Basic transcription factor 2 89 kDa subunit) (BTF2 p89) (DNA excision repair protein ERCC-3) (DNA repair protein complementing XP-B cells) (TFIIH basal transcription factor complex 89 kDa subunit) (TFIIH 89 kDa subunit) (TFIIH p89) (Xeroderma pigmentosum group B-complementing protein)
1_MGKRD 6_ RADRD 11_ KKKSR 16_ KRHYE 21_ DEEDD 26_ EEDAP 31_ GNDPQ 36_ EAVPS 41_ AAGKQ 46_ VDESG 51_ TKVDE 56_ YGAKD 61_ YRLQM 66_ PLKDD 71_ HTSRP 76_ LWVAP 81_ DGHIF 86_ LEAFS 91_ PVYKY 96_ AQDFL 101_ VAIAE 106_ PVCRP 111_ THVHE 116_ YKLTA 121_ YSLYA 126_ AVSVG 131_ LQTSD 136_ ITEYL 141_ RKLSK 146_ TGVPD 151_ GIMQF 156_ IKLCT 161_ VSYGK 166_ VKLVL 171_ KHNRY 176_ FVESC 181_ HPDVI 186_ QHLLQ 191_ DPVIR 196_ ECRLR 201_ NSEGE 206_ ATELI 211_ TETFT 216_ SKSAI 221_ SKTAE 226_ SSGGP 231_ STSRV 236_ TDPQG 241_ KSDIP 246_ MDLFD 251_ FYEQM 256_ DKDEE 261_ EEEET 266_ QTVSF 271_ EVKQE 276_ MIEEL 281_ QKRCI 286_ HLEYP 291_ LLAEY 296_ DFRND 301_ SVNPD 306_ INIDL 311_ KPTAV 316_ LRPYQ 321_ EKSLR 326_ KMFGN 331_ GRARS 336_ GVIVL 341_ PCGAG 346_ KSLVG 351_ VTAAC 356_ TVRKR 361_ CLVLG 366_ NSAVS 371_ VEQWK 376_ AQFKM 381_ WSTID 386_ DSQIC 391_ RFTSD 396_ AKDKP 401_ IGCSV 406_ AISTY 411_ SMLGH 416_ TTKRS 421_ WEAER 426_ VMEWL 431_ KTQEW 436_ GLMIL 441_ DEVHT 446_ IPAKM 451_ FRRVL 456_ TIVQA 461_ HCKLG 466_ LTATL 471_ VREDD 476_ KIVDL 481_ NFLIG 486_ PKLYE 491_ ANWME 496_ LQNNG 501_ YIAKV 506_ QCAEV 511_ WCPMS 516_ PEFYR 521_ EYVAI 526_ KTKKR 531_ ILLYT 536_ MNPNK 541_ FRACQ 546_ FLIKF 551_ HERRN 556_ DKIIV 561_ FADNV 566_ FALKE 571_ YAIRL 576_ NKPYI 581_ YGPTS 586_ QGERM 591_ QILQN 596_ FKHNP 601_ KINTI 606_ FISKV 611_ GDTSF 616_ DLPEA 621_ NVLIQ 626_ ISSHG 631_ GSRRQ 636_ EAQRL 641_ GRVLR 646_ AKKGM 651_ VAEEY 656_ NAFFY 661_ SLVSQ 666_ DTQEM 671_ AYSTK 676_ RQRFL 681_ VDQGY 686_ SFKVI 691_ TKLAG 696_ MEEED 701_ LAFST 706_ KEEQQ 711_ QLLQK 716_ VLAAT 721_ DLDAE 726_ EEVVA 731_ GEFGS 736_ RSSQA 741_ SRRFG 746_ TMSSM 751_ SGADD 756_ TVYME 761_ YHSSR 766_ SKAPS 771_ KHVHP 776_LFKRF
1: ATP-dependent 3'-5' DNA helicase/translocase (PubMed:17466626, PubMed:27193682, PubMed:33902107, PubMed:8465201, PubMed:8663148). Binds dsDNA rather than ssDNA, unzipping it in a translocase rather than classical helicase activity (PubMed:27193682, PubMed:33902107). Component of the general transcription and DNA repair factor IIH (TFIIH) core complex (PubMed:10024882, PubMed:17466626, PubMed:8157004, PubMed:8465201). When complexed to CDK-activating kinase (CAK), involved in RNA transcription by RNA polymerase II. The ATPase activity of XPB/ERCC3, but not its helicase activity, is required for DNA opening; it may wrap around the damaged DNA wedging it open, causing localized melting that allows XPD/ERCC2 helicase to anchor (PubMed:10024882, PubMed:17466626). In transcription, TFIIH has an essential role in transcription initiation (PubMed:30894545, PubMed:8157004). When the pre-initiation complex (PIC) has been established, TFIIH is required for promoter opening and promoter escape (PubMed:8157004). The ATP-dependent helicase activity of XPB/ERCC3 is required for promoter opening and promoter escape (PubMed:10024882). In transcription pre-initiation complexes induces and propagates a DNA twist to open DNA (PubMed:27193682, PubMed:33902107). Also involved in transcription-coupled nucleotide excision repair (NER) of damaged DNA (PubMed:17466626, PubMed:2111438, PubMed:8157004). In NER, TFIIH acts by opening DNA around the lesion to allow the excision of the damaged oligonucleotide and its replacement by a new DNA fragment. The structure of the TFIIH transcription complex differs from the NER-TFIIH complex; large movements by XPD/ERCC2 and XPB/ERCC3 are stabilized by XPA (PubMed:31253769, PubMed:33902107). XPA retains XPB/ERCC3 at the 5' end of a DNA bubble (mimicking DNA damage) (PubMed:31253769)