Structural highlights
Function
[TCRG1_HUMAN] Transcription factor that binds RNA polymerase II and inhibits the elongation of transcripts from target promoters. Regulates transcription elongation in a TATA box-dependent manner. Necessary for TAT-dependent activation of the human immunodeficiency virus type 1 (HIV-1) promoter.[1] [2]
Publication Abstract from PubMed
The human transcription elongation regulator TCERG1 physically couples transcription elongation and splicing events by interacting with splicing factors through its N-terminal WW domains and the hyperphosphorylated C-terminal domain (CTD) of RNA polymerase II through its C-terminal FF domains. Here, we report biochemical and structural characterization of the C-terminal three FF domains (FF4-6) of TCERG1, revealing a rigid integral domain structure of the tandem FF repeat that interacts with the hyperphosphorylated CTD (PCTD). Although FF4 and FF5 adopt a classical FF domain fold containing three orthogonally packed alpha helices and a 310 helix, FF6 contains an additional insertion helix between alpha1 and alpha2. The formation of the integral tandem FF4-6 repeat is achieved by merging the last helix of the preceding FF domain and the first helix of the following FF domain and by direct interactions between neighboring FF domains. Using peptide column binding assays and NMR titrations, we show that binding of the FF4-6 tandem repeat to the PCTD requires simultaneous phosphorylation at Ser(2), Ser(5), and Ser(7) positions within two consecutive Y(1)S(2)P(3)T(4)S(5)P(6)S(7) heptad repeats. Such a sequence-specific PCTD recognition is achieved through CTD-docking sites on FF4 and FF5 of TCERG1 but not FF6. Our study presents the first example of a nuclear factor requiring all three phospho-Ser marks within the heptad repeat of the CTD for high affinity binding and provides a molecular interpretation for the biochemical connection between the Ser(7) phosphorylation enrichment in the CTD of the transcribing RNA polymerase II over introns and co-transcriptional splicing events.
Specific Interaction of the Transcription Elongation Regulator TCERG1 with RNA Polymerase II Requires Simultaneous Phosphorylation at Ser2, Ser5, and Ser7 within the Carboxyl-terminal Domain Repeat.,Liu J, Fan S, Lee CJ, Greenleaf AL, Zhou P J Biol Chem. 2013 Apr 12;288(15):10890-901. doi: 10.1074/jbc.M113.460238. Epub, 2013 Feb 22. PMID:23436654[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Sune C, Hayashi T, Liu Y, Lane WS, Young RA, Garcia-Blanco MA. CA150, a nuclear protein associated with the RNA polymerase II holoenzyme, is involved in Tat-activated human immunodeficiency virus type 1 transcription. Mol Cell Biol. 1997 Oct;17(10):6029-39. PMID:9315662
- ↑ Goldstrohm AC, Albrecht TR, Sune C, Bedford MT, Garcia-Blanco MA. The transcription elongation factor CA150 interacts with RNA polymerase II and the pre-mRNA splicing factor SF1. Mol Cell Biol. 2001 Nov;21(22):7617-28. PMID:11604498 doi:10.1128/MCB.21.22.7617-7628.2001
- ↑ Liu J, Fan S, Lee CJ, Greenleaf AL, Zhou P. Specific Interaction of the Transcription Elongation Regulator TCERG1 with RNA Polymerase II Requires Simultaneous Phosphorylation at Ser2, Ser5, and Ser7 within the Carboxyl-terminal Domain Repeat. J Biol Chem. 2013 Apr 12;288(15):10890-901. doi: 10.1074/jbc.M113.460238. Epub, 2013 Feb 22. PMID:23436654 doi:10.1074/jbc.M113.460238
