ATP-dependent 3'-5' DNA helicase/translocase . Binds dsDNA rather than ssDNA, unzipping it in a translocase rather than classical helicase activity . Component of the general transcription and DNA repair factor IIH core complex . When complexed to CDK-activating kinase , 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 . In transcription, TFIIH has an essential role in transcription initiation . When the pre-initiation complex has been established, TFIIH is required for promoter opening and promoter escape . The ATP-dependent helicase activity of XPB/ERCC3 is required for promoter opening and promoter escape . In transcription pre-initiation complexes induces and propagates a DNA twist to open DNA . Also involved in transcription-coupled nucleotide excision repair of damaged DNA . 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 . XPA retains XPB/ERCC3 at the 5' end of a DNA bubble .

General transcription and DNA repair factor IIH helicase/translocase subunit XPB (TFIIH subunit XPB) (EC 5.6.2.4) (Basic transcription factor 2 89 kDa subunit) (BTF2 p89) (DNA 3'-5' helicase/translocase XPB) (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)

p19447

Human

WB,IF,ICC

WB 1:1000-1:5000
IF 1:200-1:500
ICC 1:200-1:500

~90 kD

Rabbit

50mM Tris-Glycine(pH 7.4), 0.15M NaCl, 40% Glycerol, 0.01% sodium azide and 0.05% BSA.

Store at -20°C. Stable for 12 months from date of receipt.