Oligomeric structure of LOV domains in Arabidopsis phototropin

Abstract 

Oligomeric structures of the four LOV domains in Arabidopsis phototropin1 (phot1) and 2 (phot2) were studied using crosslinking. Both LOV1 domains of phot1 and phot2 form a dimer independently on the light conditions, suggesting that the LOV1 domain can be a stable dimerization site of phot in vivo. In contrast, phot1-LOV2 is in a monomer–dimer equilibrium and phot2-LOV2 exists as a monomer in the dark. Blue light-induced a slight increase in the monomer population in phot1-LOV2, suggesting a possible blue light-inducible dissociation of dimers. Furthermore, blue light caused a band shift of the phot2-LOV2 monomer. CD spectra revealed the unfolding of helices and the formation of strand structures. Both light-induced changes were reversible in the dark.

Structured summary

MINT-6823377, MINT-6823391:

PHOT1 (uniprotkb:O48963) and PHOT1 (uniprotkb: O48963) bind (MI:0407) by cross-linking studies (MI:0030)

MINT-6823495, MINT-6823508:

PHOT2 (uniprotkb:P93025) and PHOT2 (uniprotkb:P93025) bind (MI:0407) by cross-linking studies (MI:0030)

Abbreviations: As, Avena sativa, At, Arabidopsis thaliana, CD, circular dichroism, FTIR, Fourier transformed infrared, FMN, flavin mononucleotide, GA, glutaraldehyde, GST, glutathione S-transferase, LOV, light, oxygen, and voltage-sensing, neo1, neochrome1, PBS, phosphate-buffered saline, phot, phototropin, phot1, phototropin1, phot2, phototropin2, SAXS, small angle X-ray scattering, UV, ultraviolet

Keywords: CD, Crosslinking, LOV domain, Oligomeric structure, Phototropin, Arabidopsis