9F6Y

CryoEM structure of Human Mediator subunit MED23 complexed with phosphorylated Elk-1 transcription factor

Summary for 9F6Y

• Entry DOI: 10.2210/pdb9f6y/pdb
• EMDB information: 50242
• Descriptor: Mediator of RNA polymerase II transcription subunit 23, Green fluorescent protein,ETS domain-containing protein Elk-1 (2 entities in total)
• Functional Keywords: mediator complex, transcription factor, med23, elk-1, phosphorylation, gene regulation
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 195922.30

Authors

Monte, D.,Verger, A.,Lens, Z.,villeret, V. (deposition date: 2024-05-02, release date: 2025-04-30)

Primary citation

Monte, D.,Lens, Z.,Dewitte, F.,Fislage, M.,Aumercier, M.,Verger, A.,Villeret, V.
Structural basis of human Mediator recruitment by the phosphorylated transcription factor Elk-1.
Nat Commun, 16:3772-3772, 2025

PubMed Abstract: One function of Mediator complex subunit MED23 is to mediate transcriptional activation by the phosphorylated transcription factor Elk-1, in response to the Ras-MAPK signaling pathway. Using cryogenic electron microscopy, we solve a 3.0 Å structure of human MED23 complexed with the phosphorylated activation domain of Elk-1. Elk-1 binds to MED23 via a hydrophobic sequence PSIHFWSTLSP containing one phosphorylated residue (S383), which forms a tight turn around the central Phenylalanine. Binding of Elk-1 induces allosteric changes in MED23 that propagate to the opposite face of the subunit, resulting in the dynamic behavior of a 19-residue segment, which alters the molecular surface of MED23. We design a specific MED23 mutation (G382F) that disrupts Elk--1 binding and consequently impairs Elk-1-dependent serum-induced activation of target genes in the Ras-Raf-MEK-ERK signaling pathway. The structure provides molecular details and insights into a Mediator subunit-transcription factor interface.

PubMed: 40263353
DOI: 10.1038/s41467-025-59014-8

Experimental method

ELECTRON MICROSCOPY (2.98 Å)