Locked 5Zs-biliverdin blocks the Meta-RA to Meta-RC transition in the functional cycle of bacteriophytochrome Agp1.
The bacteriophytochrome Agp1 was reconstituted with a locked 5Zs-biliverdin in which the C(4)=C(5) and C(5)-C(6) bonds of the methine bridge between rings A and B are fixed in the Z and syn configuration/conformation, respectively. In Agp1-5Zs the photoconversion proceeds via the Lumi-R intermediate to Meta-R(A), but the following millisecond-transition to Meta-R(C) is blocked. Consistently, no transient proton release was detected. The photoconversion of Agp1-5Zs is apparently arrested in a Meta-R(A)-like intermediate, since the subsequent syn to anti rotation around the C(5)-C(6) bond is prevented by the lock. The Meta-R(A)-like photoproduct was characterized by its distinctive CD spectrum suggesting a reorientation of ring D.
Seibeck
Sven
S
Department of Physics, Freie Universität Berlin, D-14195 Berlin, Germany.
Borucki
Berthold
B
Otto
Harald
H
Inomata
Katsuhiko
K
Khawn
Htoi
H
Kinoshita
Hideki
H
Michael
Norbert
N
Lamparter
Tilman
T
Heyn
Maarten P
MP
D026921:Amino Acid Transport Systems, Neutral / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D001664:Biliverdine / Q000737:chemistry / Q000494:pharmacology*; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D015394:Molecular Structure; D010777:Photochemistry; D010834:Phytochrome / Q000737:chemistry / Q000378:metabolism*; D011522:Protons
D026921:Amino Acid Transport Systems, Neutral; D001426:Bacterial Proteins; D011522:Protons; D010834:Phytochrome; D001664:Biliverdine