Yeast PIC-Mediator structure with RNA polymerase II C-terminal domain.
Proc Natl Acad Sci U S A
; 120(15): e2220542120, 2023 04 11.
Article
em En
| MEDLINE
| ID: mdl-37014863
ABSTRACT
For transcription initiation, RNA polymerase II (Pol II) forms a preinitiation complex (PIC) that associates with the general coactivator Mediator. Whereas atomic models of the human PIC-Mediator structure have been reported, structures for its yeast counterpart remain incomplete. Here, we present an atomic model for the yeast PIC with core Mediator, including the Mediator middle module that was previously poorly resolved and including subunit Med1 that was previously lacking. We observe three peptide regions containing eleven of the 26 heptapeptide repeats of the flexible C-terminal repeat domain (CTD) of Pol II. Two of these CTD regions bind between the Mediator head and middle modules and form defined CTD-Mediator interactions. CTD peptide 1 binds between the Med6 shoulder and Med31 knob domains, whereas CTD peptide 2 forms additional contacts with Med4. The third CTD region (peptide 3) binds in the Mediator cradle and associates with the Mediator hook. Comparisons with the human PIC-Mediator structure show that the central region in peptide 1 is similar and forms conserved contacts with Mediator, whereas peptides 2 and 3 exhibit distinct structures and Mediator interactions.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Proteínas de Saccharomyces cerevisiae
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article