Crystal structure of light activated transcription factor El222 from Erythrobacter litoralisCrystal structure of light activated transcription factor El222 from Erythrobacter litoralis

Structural highlights

3p7n is a 2 chain structure with sequence from Erythrobacter litoralis HTCC2594. The March 2015 RCSB PDB Molecule of the Month feature on Phototropin by David Goodsell is 10.2210/rcsb_pdb/mom_2015_3. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.1Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

LVHTH_ERYLH Has reversible, light-dependent DNA-binding activity. Upon illumination an internal FMN-protein adduct is formed which changes the protein conformation so that the previously sequestered DNA-binding domain is free to bind DNA. Binds to sequences within in its own promoter when illuminated but not when it has been incubated in the dark.[1]

Publication Abstract from PubMed

Light-oxygen-voltage (LOV) domains are blue light-activated signaling modules integral to a wide range of photosensory proteins. Upon illumination, LOV domains form internal protein-flavin adducts that generate conformational changes which control effector function. Here we advance our understanding of LOV regulation with structural, biophysical, and biochemical studies of EL222, a light-regulated DNA-binding protein. The dark-state crystal structure reveals interactions between the EL222 LOV and helix-turn-helix domains that we show inhibit DNA binding. Solution biophysical data indicate that illumination breaks these interactions, freeing the LOV and helix-turn-helix domains of each other. This conformational change has a key functional effect, allowing EL222 to bind DNA in a light-dependent manner. Our data reveal a conserved signaling mechanism among diverse LOV-containing proteins, where light-induced conformational changes trigger activation via a conserved interaction surface.

Structural basis of photosensitivity in a bacterial light-oxygen-voltage/helix-turn-helix (LOV-HTH) DNA-binding protein.,Nash AI, McNulty R, Shillito ME, Swartz TE, Bogomolni RA, Luecke H, Gardner KH Proc Natl Acad Sci U S A. 2011 Jun 7;108(23):9449-54. Epub 2011 May 23. PMID:21606338[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. Nash AI, McNulty R, Shillito ME, Swartz TE, Bogomolni RA, Luecke H, Gardner KH. Structural basis of photosensitivity in a bacterial light-oxygen-voltage/helix-turn-helix (LOV-HTH) DNA-binding protein. Proc Natl Acad Sci U S A. 2011 Jun 7;108(23):9449-54. Epub 2011 May 23. PMID:21606338 doi:10.1073/pnas.1100262108
  2. Nash AI, McNulty R, Shillito ME, Swartz TE, Bogomolni RA, Luecke H, Gardner KH. Structural basis of photosensitivity in a bacterial light-oxygen-voltage/helix-turn-helix (LOV-HTH) DNA-binding protein. Proc Natl Acad Sci U S A. 2011 Jun 7;108(23):9449-54. Epub 2011 May 23. PMID:21606338 doi:10.1073/pnas.1100262108

3p7n, resolution 2.10Å

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