6FHM

Crystal structure of the F47E mutant of the lipoprotein localization factor, LolA

Summary for 6FHM

• Entry DOI: 10.2210/pdb6fhm/pdb
• Related: 6F3Z 6F49
• Descriptor: Outer-membrane lipoprotein carrier protein, GLYCEROL (3 entities in total)
• Functional Keywords: lipoprotein transport, domain-swapped dimer, protein transport
• Biological source: Escherichia coli (strain K12)
• Total number of polymer chains: 2
• Total formula weight: 46110.58

Authors

Kaplan, E.,Greene, N.P.,Crow, A.,Koronakis, V. (deposition date: 2018-01-15, release date: 2018-07-25, Last modification date: 2024-01-17)

Primary citation

Kaplan, E.,Greene, N.P.,Crow, A.,Koronakis, V.
Insights into bacterial lipoprotein trafficking from a structure of LolA bound to the LolC periplasmic domain.
Proc. Natl. Acad. Sci. U.S.A., 115:E7389-E7397, 2018

PubMed Abstract: In Gram-negative bacteria, outer-membrane lipoproteins are essential for maintaining cellular integrity, transporting nutrients, establishing infections, and promoting the formation of biofilms. The LolCDE ABC transporter, LolA chaperone, and LolB outer-membrane receptor form an essential system for transporting newly matured lipoproteins from the outer leaflet of the cytoplasmic membrane to the innermost leaflet of the outer membrane. Here, we present a crystal structure of LolA in complex with the periplasmic domain of LolC. The structure reveals how a solvent-exposed β-hairpin loop (termed the "Hook") and trio of surface residues (the "Pad") of LolC are essential for recruiting LolA from the periplasm and priming it to receive lipoproteins. Experiments with purified LolCDE complex demonstrate that association with LolA is independent of nucleotide binding and hydrolysis, and homology models based on the MacB ABC transporter predict that LolA recruitment takes place at a periplasmic site located at least 50 Å from the inner membrane. Implications for the mechanism of lipoprotein extraction and transfer are discussed. The LolA-LolC structure provides atomic details on a key protein interaction within the Lol pathway and constitutes a vital step toward the complete molecular understanding of this important system.

PubMed: 30012603
DOI: 10.1073/pnas.1806822115

Experimental method

X-RAY DIFFRACTION (2.39 Å)