Structural analysis of HTL and D14 proteins reveals the basis for ligand selectivity in Striga

• DOI: 10.1038/s41467-018-06452-2
• Publication Date: 2018-09-20T16:19:00Z
• Authors: Yuqun Xu; Takuya Miyakawa; Shohei Nosaki; Akira Nakamura; Ying Lyu; Hidemitsu Nakamura; Umeharu Ohto; Hanako Ishida; Toshiyuki Shimizu; Tadao Asami; Masaru Tanokura
• Keywords: Strigolactone; Striga hermonthica

HYPOSENSITIVE TO LIGHT (HTL) and DWARF14 (D14) mediate the perception of karrikin strigolactone, which stimulates germination parasitic weed Striga. However, their role in seeds is poorly understood, basis for differing responsiveness remains unclear. Here, we show that Striga hermonthica HTL proteins (ShHTLs) 'conserved' 'intermediate' clades are able to bind karrikin. The 'divergent' clade hydrolyze strigolactone. Unexpectedly, find ShD14 also capable hydrolyzing Through comparative analysis ShHTLs crystal structures, provide insights into selectivity. Moreover, both divergent ShHTLs, but not conserved intermediate can interact with putative downstream signaling component ShMAX2 presence synthetic rac-GR24. These findings insight how strigolactone perceived ligand specificity determined.