TY - JOUR
T1 - Quaternary structure of LOV-domain containing polypeptide of Arabidopsis FKF1 protein
AU - Nakasako, Masayoshi
AU - Matsuoka, Daisuke
AU - Zikihara, Kazunori
AU - Tokutomi, Satoru
N1 - Funding Information:
This work was supported by MEXT Japan to M.N. (No. 15076210) and S.T. (No. 13139205). The SAXS experiments were carried out as proposals to SPring-8 (Nos. 2003B-0141 and 2004A-0317).
PY - 2005/2/14
Y1 - 2005/2/14
N2 - Flavin-binding, Kelch repeat, F-box (FKF1) protein is a photoreceptor to regulate flowering of Arabidopsis. The protein has a light, oxygen and voltage (LOV)-sensing domain binding a flavin mononucleotide. The photo-activation of the domain is an indispensable step to initiate the cellular signaling for flowering. In the present study, a LOV-containing polypeptide of FKF1 was prepared by an overexpression system, and the quaternary structure of it was studied by size exclusion chromatography and small-angle X-ray scattering. The apparent molecular weight from chromatography suggested a globular trimeric or an anisotropic-shaped dimeric association of the polypeptide in solution. The scattering experiment demonstrated a dimeric association of the polypeptides with an elongated molecular shape displaying the radius of gyration of 27 Å and the maximum dimension of 94 Å. The molecular shape simulated from scattering profiles suggests an antiparallel association of the LOV domains in the dimer. Though the absorption spectrum of blue-light irradiated polypeptide was stable in the photoactivated state for a long period, the scattering profiles showed very small changes between the dark and light conditions. Based on the homologies in the amino-acid sequences and the scattering profiles, these results are discussed in connection with the structures and function of LOV domains of phototropin.
AB - Flavin-binding, Kelch repeat, F-box (FKF1) protein is a photoreceptor to regulate flowering of Arabidopsis. The protein has a light, oxygen and voltage (LOV)-sensing domain binding a flavin mononucleotide. The photo-activation of the domain is an indispensable step to initiate the cellular signaling for flowering. In the present study, a LOV-containing polypeptide of FKF1 was prepared by an overexpression system, and the quaternary structure of it was studied by size exclusion chromatography and small-angle X-ray scattering. The apparent molecular weight from chromatography suggested a globular trimeric or an anisotropic-shaped dimeric association of the polypeptide in solution. The scattering experiment demonstrated a dimeric association of the polypeptides with an elongated molecular shape displaying the radius of gyration of 27 Å and the maximum dimension of 94 Å. The molecular shape simulated from scattering profiles suggests an antiparallel association of the LOV domains in the dimer. Though the absorption spectrum of blue-light irradiated polypeptide was stable in the photoactivated state for a long period, the scattering profiles showed very small changes between the dark and light conditions. Based on the homologies in the amino-acid sequences and the scattering profiles, these results are discussed in connection with the structures and function of LOV domains of phototropin.
KW - FKF1 protein
KW - LOV domain
KW - Photoperiodism
KW - Quaternary structure
KW - Small-angle X-ray scattering
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U2 - 10.1016/j.febslet.2004.12.078
DO - 10.1016/j.febslet.2004.12.078
M3 - Article
C2 - 15710392
AN - SCOPUS:13844261202
SN - 0014-5793
VL - 579
SP - 1067
EP - 1071
JO - FEBS Letters
JF - FEBS Letters
IS - 5
ER -