Femto- to Microsecond Photodynamics of an Unusual Bacteriophytochrome.
A bacteriophytochrome from Stigmatella aurantiaca is an unusual member of the bacteriophytochrome family that is devoid of hydrogen bonding to the carbonyl group of ring D of the biliverdin (BV) chromophore. The photodynamics of BV in SaBphP1 wild type and the single mutant T289H reintroducing hydrogen bonding to ring D show that the strength of this particular weak interaction determines excited-state lifetime, Lumi-R quantum yield, and spectral heterogeneity. In particular, excited-state decay is faster in the absence of hydrogen-bonding to ring D, with excited-state half-lives of 30 and 80 ps for wild type and the T289H mutant, respectively. Concomitantly, the Lumi-R quantum yield is two times higher in wild type as compared with the T289H mutant. Furthermore, the spectral heterogeneity in the wild type is significantly higher than that in the T289H mutant. By extending the observable time domain to 25 μs, we observe a new deactivation pathway from the Lumi-R intermediate in the 100 ns time domain that corresponds to a backflip of ring D to the original Pr 15Za isomeric state.
†Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
Tilo
T
Mathes
†Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
Janneke
J
Ravensbergen
†Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
Miroslav
M
Kloz
†Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
Tobias
T
Gleichmann
‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States.
Kevin D
KD
Gallagher
‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States.
Nicole C
NC
Woitowich
‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States.
Rachael
R
St Peter
‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States.
Svetlana E
SE
Kovaleva
‡Department of Biology, Northeastern Illinois University, 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States.
Emina A
EA
Stojković
†Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
John T M
JT
Kennis
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001664:Biliverdine / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D006207:Half-Life; D006860:Hydrogen Bonding; D062105:Molecular Docking Simulation; D016297:Mutagenesis, Site-Directed; D009231:Myxococcales / Q000378:metabolism*; D010834:Phytochrome / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D013053:Spectrophotometry
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D010834:Phytochrome; D001664:Biliverdine
biliverdin; hydrogen bonding; near-IR fluorescent protein; photoreceptor