Orientation of the chromophore transition moment in the 4‐leaved shape model for pea phytochrome molecule in the red‐light absorbing form and its rotation induced by the phototransformation to the far‐red‐light absorbing form

FEBS Letters

Tokutomi, Satoru¹  Mimuro, Mamoru² 

[1] Division of Biological Regulation National Institute for Basic Biology, Okazaki 444, Japan;Division of Bioenergetics, National Institute for Basic Biology, Okazaki 444, Japan

关键词: Phytochrome;    Linear dichroism;    Rotation of transition moment;    Phototransformation;    Oriented molecule;    Gel squeezing;    kDa;    kilodaltons;    Pr and Pfr;    red-light-absorbing form and far-red-light-absorbing form of phytochrome;    LD;    linear dichroism;   

DOI  :  10.1016/0014-5793(89)81119-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Orientation of the chromophore transition moment in pea phytochrome (subunit molecular mass, 114 kDa) in the red-light-absorbing form (P_r) and its rotation induced by the phototransformation to the far-red-light-absorbing (P_fr) form was studied by measuring linear dichroism of oriented phytochrome prepared by a ‘gel squeezing method’. The phytochrome in P_r showed a negative linear dichroism. On the contrary, the P_fr form showed positive linear dichroism. Assuming that the molecular axis for the two-fold rotational symmetry in the ‘4-leaved shape model’ proposed recently for the dimeric molecular structure of the phytochrome [(1989) FEBS Lett. 247, 139–142], is oriented in parallel with the direction of the external constraint, the average azimuthal angle between the molecular axis and the transition moment of the chromophore was calculated as 59° or 121° for P_r and 52° or 128° for P_fr. These results explain well the polarotropic responses by phytochrome observed in plant organisms.

【 授权许可】

Unknown