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  • The basic leucine zipper stress response regulator Yap5 senses high-iron conditions by coordination of [2Fe-2S] clusters.

The basic leucine zipper stress response regulator Yap5 senses high-iron conditions by coordination of [2Fe-2S] clusters.

Molecular and cellular biology (2014-11-05)
Nicole Rietzschel, Antonio J Pierik, Eckhard Bill, Roland Lill, Ulrich Mühlenhoff
ABSTRACT

Iron is an essential, yet at elevated concentrations toxic trace element. To date, the mechanisms of iron sensing by eukaryotic iron-responsive transcription factors are poorly understood. The Saccharomyces cerevisiae transcription factor Yap5, a member of the Yap family of bZIP stress response regulators, administrates the adaptive response to high-iron conditions. Despite the central role of the iron-sensing process for cell viability, the molecule perceived by Yap5 and the underlying regulatory mechanisms are unknown. Here, we show that Yap5 senses high-iron conditions by two Fe/S clusters bound to its activator domain (Yap5-AD). The more stable iron-regulatory Fe/S cluster at the N-terminal cysteine-rich domain (n-CRD) of Yap5 is detected in vivo and in vitro. The second cluster coordinated by the C-terminal CRD can only be shown after chemical reconstitution, since it is bound in a labile fashion. Both clusters are of the [2Fe-2S] type as characterized by UV/visible (UV/Vis), circular dichroism, electron paramagnetic resonance (EPR), and Mössbauer spectroscopy. Fe/S cluster binding to Yap5-AD induces a conformational change that may activate transcription. The cluster-binding motif of the n-CRD domain is highly conserved in HapX-like transcription factors of pathogenic fungi and thus may represent a general sensor module common to many eukaryotic stress response regulators.

MATERIALS
Product Number
Brand
Product Description

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Iron, foil, light tested, 25x25mm, thickness 0.015mm, 99.85%
Iron, foil, 10mm disks, thickness 0.038mm, hard, 99.5%
Iron, foil, 15mm disks, thickness 0.0125mm, 99.85%
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Iron, foil, 15mm disks, thickness 0.020mm, 99.85%
Iron, foil, 10mm disks, thickness 0.25mm, as rolled, 99.99+%
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Iron, foil, 1m coil, thickness 0.38mm, hard, 99.5%
Iron, foil, 15mm disks, thickness 0.15mm, hard, 99.5%
Iron, foil, 20m coil, thickness 0.038mm, hard, 99.5%
Iron, foil, 10mm disks, thickness 0.075mm, as rolled, 99.99+%
Iron, foil, 1m coil, thickness 0.025mm, hard, 99.5%
Iron, foil, 15mm disks, thickness 0.008mm, 99.85%
Iron, foil, 15mm disks, thickness 0.125mm, hard, 99.5%
Iron, foil, 10mm disks, thickness 0.125mm, as rolled, 99.99+%
Iron, foil, 1m coil, thickness 0.05mm, hard, 99.5%
Iron, foil, 15mm disks, thickness 0.1mm, hard, 99.5%
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Iron, foil, 10mm disks, thickness 0.9mm, as rolled, 99.5%
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