Summary: TATA-binding related factor (TRF) of subunit 20 of Mediator complex
TATA-binding related factor (TRF) of subunit 20 of Mediator complex Provide feedback
This family of proteins is related to TATA-binding protein (TBP). TBP is a highly conserved RNA polymerase II general transcription factor that binds to the core promoter and initiates assembly of the preinitiation complex. Human TRF has been shown to associate with an RNA polymerase II-SRB complex . This Med20 subunit of Mediator is found in the non-essential part of the head .
Bourbon HM, Aguilera A, Ansari AZ, Asturias FJ, Berk AJ, Bjorklund S, Blackwell TK, Borggrefe T, Carey M, Carlson M, Conaway JW, Conaway RC, Emmons SW, Fondell JD, Freedman LP, Fukasawa T, Gustafsson CM, Han M, He X, Herman PK, Hinnebusch AG, Holmberg S, , Mol Cell. 2004;14:553-557.: A unified nomenclature for protein subunits of mediator complexes linking transcriptional regulators to RNA polymerase II. PUBMED:15175151 EPMC:15175151
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This tab holds annotation information from the InterPro database.
InterPro entry IPR013921
The Mediator complex is a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. The Mediator complex, having a compact conformation in its free form, is recruited to promoters by direct interactions with regulatory proteins and serves for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors. On recruitment the Mediator complex unfolds to an extended conformation and partially surrounds RNA polymerase II, specifically interacting with the unphosphorylated form of the C-terminal domain (CTD) of RNA polymerase II. The Mediator complex dissociates from the RNA polymerase II holoenzyme and stays at the promoter when transcriptional elongation begins.
The Mediator complex is composed of at least 31 subunits: MED1, MED4, MED6, MED7, MED8, MED9, MED10, MED11, MED12, MED13, MED13L, MED14, MED15, MED16, MED17, MED18, MED19, MED20, MED21, MED22, MED23, MED24, MED25, MED26, MED27, MED29, MED30, MED31, CCNC, CDK8 and CDC2L6/CDK11.
The subunits form at least three structurally distinct submodules. The head and the middle modules interact directly with RNA polymerase II, whereas the elongated tail module interacts with gene-specific regulatory proteins. Mediator containing the CDK8 module is less active than Mediator lacking this module in supporting transcriptional activation.
- The head module contains: MED6, MED8, MED11, SRB4/MED17, SRB5/MED18, ROX3/MED19, SRB2/MED20 and SRB6/MED22.
- The middle module contains: MED1, MED4, NUT1/MED5, MED7, CSE2/MED9, NUT2/MED10, SRB7/MED21 and SOH1/MED31. CSE2/MED9 interacts directly with MED4.
- The tail module contains: MED2, PGD1/MED3, RGR1/MED14, GAL11/MED15 and SIN4/MED16.
- The CDK8 module contains: MED12, MED13, CCNC and CDK8.
Individual preparations of the Mediator complex lacking one or more distinct subunits have been variously termed ARC, CRSP, DRIP, PC2, SMCC and TRAP.
Proteins in this entry are subunit Med20 of the Mediator complex, and is found in the non-essential part of the head [PUBMED:15175151]. and related to the TATA-binding protein (TBP). TBP is a highly conserved RNA polymerase II general transcription factor that binds to the core promoter and initiates assembly of the pre-initiation complex. Human TRF has been shown to associate with an RNA polymerase II-SRB complex [PUBMED:9933582].
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||mediator complex (GO:0016592)|
|Molecular function||RNA polymerase II transcription cofactor activity (GO:0001104)|
|Biological process||regulation of transcription from RNA polymerase II promoter (GO:0006357)|
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Curation and family details
|Author:||Mistry J, Wood V|
|Number in seed:||32|
|Number in full:||235|
|Average length of the domain:||213.80 aa|
|Average identity of full alignment:||26 %|
|Average coverage of the sequence by the domain:||92.51 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||6|
|Download:||download the raw HMM for this family|
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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Med20 domain has been found. There are 11 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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