pfam12432: INTS1_RP2B-bd (This model is not part of the current CDD release)
Integrator complex subunit 1, RP2B-binding domain
Integrator (INT) complex is involved in the small nuclear RNAs (snRNA) U1 and U2 transcription and in their 3'-box-dependent processing. It binds the C-terminal domain (CTD) of RNA polymerase II (Pol II) and functions as an RNA endonuclease to cleave different classes of RNAs, regulating the transcription of both protein-coding genes and noncoding elements. Integrator also associates with protein phosphatase 2A (PP2A) core enzyme to form the INTAC complex which regulates transcription through dephosphorylation of Pol II CTD. This entry includes the Integrator complex subunit 1 (INTS1) which forms the backbone module of the complex (it consists of four modules: backbone, shoulder, phosphatase and endonuclease) through the association with INTS2 and INTS7 to form a rigid scaffold. The backbone and shoulder modules form a central cruciform scaffold. INTS1 is an all-alpha helical protein with four repetitive helix hairpin domains towards the C-terminal (R1-R4). This entry represents a domain found at the N-terminal of INTS1, which interacts with Pol II subunit RPB2 and form interface A.
Jiyao W et al.(2023). "The conserved domain database in 2023.",