4D7X

Solution Structure of the Mediator Gall11 KIX Domain of C. Glabrata

Summary for 4D7X

• Entry DOI: 10.2210/pdb4d7x/pdb
• NMR Information: BMRB: 25372
• Descriptor: MEDIATOR OF RNA POLYMERASE II TRANSCRIPTION SUBUNIT 15 (1 entity in total)
• Functional Keywords: transcription
• Biological source: CANDIDA GLABRATA
• Total number of polymer chains: 1
• Total formula weight: 9743.16

Authors

Boeszoermenyi, A.,Wagner, G.,Naar, A.M.,Arthanari, H. (deposition date: 2014-11-30, release date: 2015-12-09, Last modification date: 2024-06-19)

Primary citation

Nishikawa, J.L.,Boeszoermenyi, A.,Vale-Silva, L.A.,Torelli, R.,Posteraro, B.,Sohn, Y.,Ji, F.,Gelev, V.,Sanglard, D.,Sanguinetti, M.,Sadreyev, R.I.,Mukherjee, G.,Bhyravabhotla, J.,Buhrlage, S.J.,Gray, N.S.,Wagner, G.,Naar, A.M.,Arthanari, H.
Inhibiting Fungal Multidrug Resistance by Disrupting an Activator-Mediator Interaction.
Nature, 530:485-, 2016

PubMed Abstract: Eukaryotic transcription activators stimulate the expression of specific sets of target genes through recruitment of co-activators such as the RNA polymerase II-interacting Mediator complex. Aberrant function of transcription activators has been implicated in several diseases. However, therapeutic targeting efforts have been hampered by a lack of detailed molecular knowledge of the mechanisms of gene activation by disease-associated transcription activators. We previously identified an activator-targeted three-helix bundle KIX domain in the human MED15 Mediator subunit that is structurally conserved in Gal11/Med15 Mediator subunits in fungi. The Gal11/Med15 KIX domain engages pleiotropic drug resistance transcription factor (Pdr1) orthologues, which are key regulators of the multidrug resistance pathway in Saccharomyces cerevisiae and in the clinically important human pathogen Candida glabrata. The prevalence of C. glabrata is rising, partly owing to its low intrinsic susceptibility to azoles, the most widely used antifungal agent. Drug-resistant clinical isolates of C. glabrata most commonly contain point mutations in Pdr1 that render it constitutively active, suggesting that this transcriptional activation pathway represents a linchpin in C. glabrata multidrug resistance. Here we perform sequential biochemical and in vivo high-throughput screens to identify small-molecule inhibitors of the interaction of the C. glabrata Pdr1 activation domain with the C. glabrata Gal11A KIX domain. The lead compound (iKIX1) inhibits Pdr1-dependent gene activation and re-sensitizes drug-resistant C. glabrata to azole antifungals in vitro and in animal models for disseminated and urinary tract C. glabrata infection. Determining the NMR structure of the C. glabrata Gal11A KIX domain provides a detailed understanding of the molecular mechanism of Pdr1 gene activation and multidrug resistance inhibition by iKIX1. We have demonstrated the feasibility of small-molecule targeting of a transcription factor-binding site in Mediator as a novel therapeutic strategy in fungal infectious disease.

PubMed: 26886795
DOI: 10.1038/NATURE16963

Experimental method

SOLUTION NMR