Hide and Seek

Abstract

Microbiology![Figure][1] CREDIT: SANCHEZ-VALLET ET AL., ELIFE2 (2013) Plants and their fungal pathogens are at war. Plant surface receptors, which contain lysin motifs (LysMs), sense fungal chitin oligomers, which are basic components of fungal cell walls, and thereby trigger immune defenses against the fungus. The fungi, in turn, have evolved molecular countermeasures. Sanchez-Vallet et al. report structural studies of a fungal effector protein, Ecp6, which is secreted by the leaf mold Cladosporium fulvum and provides a means for the pathogen to hide from the host. Ecp6 also contains LysM, but unlike the plant's receptors, the fungal motifs dimerize in the presence of its own chitin to form a deeply buried groove that binds chitin with high affinity and keeps it out of sight of the plant's immune responses. LysM seems to be ubiquitous among fungi and may represent a common mechanism by which such pathogens can evade host defenses. It is interesting that two evolutionarily distant organisms have converged on the ability to recognize the same molecule via the same motif that resides in divergent proteins and with antagonistic effect. eLife 2 , e00790 (2013). [1]: pending:yes