The PHY domain is required for conformational stability and spectral integrity of the bacteriophytochrome from Deinococcus radiodurans.
Bacteriophytochrome from Deinococcus radiodurans (DrBphP) is a plant phytochrome homolog. To investigate the interaction of chromophore and protein structure, we purified recombinant DrBphP and performed biochemical analyses. Differences of apo- and holo-protein in electrophoretic properties in native gels and their susceptibility to trypsin indicate changes in both the conformation and surface topography of this protein as a result of chromophore assembly. Furthermore, proteolysis to Pr and Pfr conformers displayed distinctive cleavage patterns with a noticeable Pr-specific tryptic fragment. Of interest, a prolonged tryptic digestion showed a more severe impact upon the Pfr form. Most importantly, when we assessed the extent of dark reversion to evaluate the role of the cleaved part, a rapidly accelerated reversion was observed upon cleavage at residues 329-505 corresponding to the PHY domain. Our data thus show that the PHY domain is necessary for the Pfr stabilization and spectral integrity of DrBphP.
Yoon
Joo-Mi
JM
Plant Metabolism Research Center & Graduate School of Biotechnology, Kyung Hee University, 1 Seocheon Dong, Yongin 446-701, Republic of Korea.
Hahn
Tae-Ryong
TR
Cho
Man-Ho
MH
Jeon
Jong-Seong
JS
Bhoo
Seong Hee
SH
Kwon
Yong-Kook
YK
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D034301:Deinococcus / Q000378:metabolism*; D010834:Phytochrome / Q000737:chemistry*; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D013057:Spectrum Analysis; D014357:Trypsin / Q000737:chemistry
D001426:Bacterial Proteins; D010834:Phytochrome; D014357:Trypsin