A novel LPS-dependent outer membrane-anchoring mechanism for T9SS substrates enables engineered enzyme display and whole-cell PET degradation in <i>Cytophaga hutchinsonii</i>.

ABSTRACT: Robust surface display systems are crucial for engineering Gram-negative bacteria as whole-cell biocatalysts. In the efficient cellulose degrader Cytophaga hutchinsonii, cellulases are secreted by the Type IX Secretion System (T9SS), yet their mechanism for outer membrane anchoring remained unknown. Here, we report a novel lipopolysaccharide (LPS)-dependent anchoring mechanism for T9SS substrates. We initially found that the anchoring of T9SS substrates to the outer membrane involves a modification, evident as a characteristic ladder-like pattern on PVDF membrane. By expressing heterologous proteins fused to the CTDs of specific cellulases, we demonstrated that this modification and anchoring are strictly CTD-dependent. Using bioinformatic analysis and gene deletion, we identified W

SUBMITTER: Song W 

PROVIDER: S-EPMC12860637 | biostudies-literature | 2026 Sep

REPOSITORIES: biostudies-literature