title: The PHY domain is required for conformational stability and spectral integrity of the bacteriophytochrome from Deinococcus radiodurans.
abstract: 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.
authors.affiliation: Plant Metabolism Research Center & Graduate School of Biotechnology, Kyung Hee University, 1 Seocheon Dong, Yongin 446-701, Republic of Korea.
authors.forename: Joo-Mi
authors.initials: JM
authors.lastname: Yoon
authors.forename: Tae-Ryong
authors.initials: TR
authors.lastname: Hahn
authors.forename: Man-Ho
authors.initials: MH
authors.lastname: Cho
authors.forename: Jong-Seong
authors.initials: JS
authors.lastname: Jeon
authors.forename: Seong Hee
authors.initials: SH
authors.lastname: Bhoo
authors.forename: Yong-Kook
authors.initials: YK
authors.lastname: Kwon
mesh_terms: 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
chemical_list: D001426:Bacterial Proteins; D010834:Phytochrome; D014357:Trypsin