FIGURE 11.

Model for DrBphP photoconversion. Model involves the reorientation of the sister PHY domains relative to the GAF domains through light-induced conformational changes in the PHY domain hairpin from β-strand to helical and altered contacts with the GAF domain. These modifications reorient and/or increase the mobility of the sister HK domains through alterations of the bowed helical spines to ultimately impact phosphotransferase activity of the dimer. HP, hairpin. Pfr and Pfr′ represent the two photoactivated states observed by SPEM.