Molecular Basis for Catalysis and Regulation of the Strigolactone Catabolic Enzyme CXE15.

ABSTRACT: Strigolactones (SLs) are pivotal plant hormones involved in developmental, physiological, and adaptive processes. SLs also facilitate symbiosis with arbuscular mycorrhizal fungi and trigger germination of root parasitic Striga plants. The carboxylesterase CXE15, recently identified as the SL catabolic enzyme in Arabidopsis thaliana, plays a crucial role in regulating SL levels. Our study elucidates the structural and regulatory mechanisms of CXE15. We present four crystal structures capturing the conformational dynamics of CXE15, revealing a unique N-terminal extension (Nt) that transitions from a β-sheet in monomers to an intertwined helical structure in dimers. Only the dimeric form is catalytically active, as it forms a hydrophobic cavity for SLs between its two active sites. The modera

SUBMITTER: Shahul Hameed UF 

PROVIDER: S-EPMC12638876 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature