Structural insights into peptidoglycan glycosidase EtgA binding to the inner rod protein EscI of the type III secretion system via a designed EscI-EtgA fusion protein.

ABSTRACT: Bacteria express lytic enzymes such as glycosidases, which have potentially self-destructive peptidoglycan (PG)-degrading activity and, therefore, require careful regulation in bacteria. The PG glycosidase EtgA is regulated by localization to the assembling type III secretion system (T3SS), generating a hole in the PG layer for the T3SS to reach the outer membrane. The EtgA localization was found to be mediated via EtgA interacting with the T3SS inner rod protein EscI. To gain structural insights into the EtgA recognition of EscI, we determined the 2.01 Å resolution structure of an EscI (51-87)-linker-EtgA fusion protein designed based on AlphaFold2 predictions. The structure revealed EscI residues 72-87 forming an α-helix interacting with the backside of EtgA, distant from the active site

SUBMITTER: Boorman J 

PROVIDER: S-EPMC10880428 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature