Journal: Nature Communications
Article Title: Origin of the multi-phasic quenching dynamics in the BLUF domains across the species
doi: 10.1038/s41467-023-44565-5
Figure Lengend Snippet: Three active-site conformations, including the central FMN (gray), Gln (Q, cyan/green/yellow), and Tyr (Y, gray), as well as the nearby Trp (W, cyan/green/yellow) in BLUF domains. W in NH in configuration ( a ) is adopted from one X-ray structure of the AppA BLUF domain (PDB: 1YRX ). A preferred no-proton relay geometry of Tyr and Gln is depicted according to previous free energy calculations . W in NH out ( b ) and W out ( c ) configurations are adopted from the two subunits of Sy PixD tetramer (PDB: 2HFO ), chain D, and chain B, respectively. Both favor a proton transfer geometry where Tyr OH is H bonded to Gln Oε1, and Gln Nε2H is H bonded to FMN N5 , . Edge-to-edge distances (double arrows) between the nearby Trp and FMN are shown in each configuration. Possible proton transfer pathways are drawn in dashed lines.
Article Snippet: The 5FW and 7FW labeled protein samples, i.e., WT and YnF mutants of Oa PAC 1-102 , Sy PixD 1-150 , and AppA 1-124 BLUF domains, were expressed in tryptophan auxotrophy RF12 strain (a gift from Robert Gennis & Toshio Iwasaki, Addgene plasmid # 62077) – .
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