SASDB24: Aureochrome 1a bZIP-LOV module: PtAUREO1a bZIP-LOV (Light oxygen ...

Basic information

Entry

Database: SASBDB / ID: SASDB24

Sample

Aureochrome 1a bZIP-LOV module: PtAUREO1a bZIP-LOV (Light oxygen voltage) module (light state, Tris)

• Aureochrome 1a bZIP-LOV module (protein), PtAUREO1a bZIP-LOV, Phaeodactylum tricornutum

• Biological species: Phaeodactylum tricornutum (Diatom)
• Citation: Journal: Nucleic Acids Res / Year: 2016; Title: Allosteric communication between DNA-binding and light-responsive domains of diatom class I aureochromes.; Authors: Ankan Banerjee / Elena Herman / Manuel Serif / Manuel Maestre-Reyna / Sebastian Hepp / Richard Pokorny / Peter G Kroth / Lars-Oliver Essen / Tilman Kottke / ; Abstract: The modular architecture of aureochrome blue light receptors, found in several algal groups including diatoms, is unique by having the LOV-type photoreceptor domain fused to the C-terminus of its putative effector, an N-terminal DNA-binding bZIP module. The structural and functional understanding of aureochromes' light-dependent signaling mechanism is limited, despite their promise as an optogenetic tool. We show that class I aureochromes 1a and 1c from the diatom Phaeodactylum tricornutum are regulated in a light-independent circadian rhythm. These aureochromes are capable to form functional homo- and heterodimers, which recognize the ACGT core sequence within the canonical 'aureo box', TGACGT, in a light-independent manner. The bZIP domain holds a more folded and less flexible but extended conformation in the duplex DNA-bound state. FT-IR spectroscopy in the absence and the presence of DNA shows light-dependent helix unfolding in the LOV domain, which leads to conformational changes in the bZIP region. The solution structure of DNA bound to aureochrome points to a tilted orientation that was further validated by molecular dynamics simulations. We propose that aureochrome signaling relies on an allosteric pathway from LOV to bZIP that results in conformational changes near the bZIP-DNA interface without major effects on the binding affinity.

Contact author

• Lars-Oliver Essen (Philipps-Universität Marburg)

Models

Sample

• Sample: Name: Aureochrome 1a bZIP-LOV module: PtAUREO1a bZIP-LOV (Light oxygen voltage) module (light state, Tris); Specimen concentration: 0.63-2.50
• Buffer: Name: Tris / Concentration: 10.00 mM / pH: 8 / Composition: 300 mM NaCl

Entity #312

Name: PtAUREO1a bZIP-LOV / Type: protein / Description: Aureochrome 1a bZIP-LOV module / Formula weight: 28.655 / Num. of mol.: 2 / Source: Phaeodactylum tricornutum
Sequence:

MGSSHHHHHH SSGLVPRGSH MDRKMSEQQK VERRERNREH AKRSRIRKKF LLESLQQSVS LLKEENEKLK TSIRSHLGEE KADTLIDSAN NNKTDVDGLL ASSQGIANKV LDDPDFSFIK ALQTAQQNFV VTDPSLPDNP IVYASQGFLN LTGYSLDQIL GRNCRFLQGP ETDPKAVERI RKAIEQGNDM SVCLLNYRVD GTTFWNQFFI AALRDAGGNV TNFVGVQCKV SDQYAATVTK QQEEEEEAAA NDDED

Experimental information

• Beam: Instrument name: ESRF BM29 / City: Grenoble / 国: France / Type of source: X-ray synchrotron / Wavelength: 0.93 Å / Dist. spec. to detc.: 2.43 mm
• Detector: Name: Pilatus 1M

Scan

Title: Aureochrome 1a bZIP-LOV module (light in Tris-HCl) / Measurement date: Nov 6, 2014 / Storage temperature: 4 °C / Cell temperature: 4 °C / Exposure time: 20 sec. / Number of frames: 10 / Unit: 1/nm /

	Min	Max
Q	0.0364	3.8229

Distance distribution function P(R)

Sofotware P(R): GNOM 5.0 / Number of points: 556 /

	Min	Max
Q	0.178551	2.80875
P(R) point	1	556
R	0	12.54

Result

Type of curve: merged /

	Experimental	Porod
MW	43.5 kDa	60.5 kDa
Volume	-	121.45 nm3

	P(R)	Guinier
Forward scattering, I0	42.66	43.62
Radius of gyration, Rg	3.872 nm	3.89 nm

	Min	Max
D	-	12.54
Guinier point	8	60