Molecular mechanism for lateral lipid diffusion between the outer membrane external leaflet and a beta-barrel hydrocarbon ruler.

ABSTRACT: Membrane-intrinsic enzymes are embedded in lipids, yet how such enzymes interrogate lipid substrates remains a largely unexplored fundamental question. The outer membrane phospholipid:lipid A palmitoyltransferase PagP combats host immune defenses during infection and selects a palmitate chain using its beta-barrel interior hydrocarbon ruler. Both a molecular embrasure and crenel in Escherichia coli PagP display weakened transmembrane beta-strand hydrogen bonding to provide potential lateral routes for diffusion of the palmitoyl group between the hydrocarbon ruler and outer membrane external leaflet. Prolines in strands A and B lie beneath the dynamic L1 surface loop flanking the embrasure, whereas the crenel is flanked by prolines in strands F and G. Reversibly barricading the embrasure pr

SUBMITTER: Khan MA 

PROVIDER: S-EPMC5007123 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature