The PHY domain is required for conformational stability and spectral integrity of the bacteriophytochrome from Deinococcus radiodurans

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• 作者：Joo-Mi Yoon ; Tae-Ryong Hahn ; Man-Ho Cho ; Jong-Seong Jeon ; Seong Hee Bhoo ; Yong-Kook Kwon
• 关键词：DrBphP ; Phytochrome ; Surface topology ; Dark reversion ; Pfr stabilization
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2008
• 出版时间：16 May 2008
• 年：2008
• 卷：369
• 期：4
• 页码：1120-1124
• 全文大小：726 K

文摘

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.