DpaA Detaches Braun’s Lipoprotein from Peptidoglycan
Matthias Winkle, Víctor M. Hernández-Rocamora, Karthik Pullela, Emily C. A. Goodall, Alessandra M. Martorana, Joe Gray, Ian R. Henderson, Alessandra Polissi, Waldemar Vollmer
Abstract
, and about one-third of the Lpp molecules become covalently attached to tripeptides in peptidoglycan. The attachment of Lpp to peptidoglycan stabilizes the cell envelope and is crucial for the outer membrane to function as a permeability barrier for a range of toxic molecules and antibiotics. So far, the attachment of Lpp to peptidoglycan has been considered to be irreversible. We have now identified an amidase, DpaA, which is capable of detaching Lpp from peptidoglycan, and we show that the detachment of Lpp is important under certain stress conditions. DpaA-like proteins are present in many Gram-negative bacteria and may have different substrates in these species.