Lipopolysaccharide (LPS) is a major component of the outer leaflet of the outer membrane (OM) of Gram-negative bacteria. Lipid A functions as the hydrophobic membrane anchor of LPS and is linked via a core oligosaccharide to the long chain polysaccharide known as O-antigen. The lipid A-core portion (known as “rough” LPS (R-LPS)) is synthesized by a conserved pathway involving proteins on the cytoplasmic surface of the inner membrane (IM) and is then transported across the IM by an essential ATP-binding cassette (ABC) transporter, MsbA. Recently, five additional essential E. coli proteins (LptA, LptB, LptC (formerly YrbK), LptF (formerly YjgP), and LptG (formerly YjgQ)) have been implicated in LPS transport to the OM. LptA is a candidate for the chaperone delivering nascent LPS molecules to LptDE in the OM. Here you can see a recent crystal structure of the LptA protein from Escherichia coli (PDB code: 8GAJ)

#molecularart ... #immolecular ... #periplasm ... #gramnegative ... #cellwall ... #LptA ... #peptidoglycan ... #xray

Structure rendered with @proteinimaging and depicted with @corelphotopaint