3POQ

Crystal structure of E.coli OmpF porin in lipidic cubic phase: space group H32, small unit cell

Summary for 3POQ

• Entry DOI: 10.2210/pdb3poq/pdb
• Related: 3POU 3POX
• Descriptor: OmpF protein, (2R)-2,3-dihydroxypropyl (9Z)-octadec-9-enoate, THIOCYANATE ION, ... (4 entities in total)
• Functional Keywords: beta barrel, membrane protein, solute transport, pore
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 45488.92

Authors

Efremov, R.G.,Sazanov, L.A. (deposition date: 2010-11-23, release date: 2012-03-07, Last modification date: 2023-11-01)

Primary citation

Efremov, R.G.,Sazanov, L.A.
Structure of Escherichia coli OmpF porin from lipidic mesophase.
J.Struct.Biol., 178:311-318, 2012

PubMed Abstract: Outer membrane protein F, a major component of the Escherichia coli outer membrane, was crystallized for the first time in lipidic mesophase of monoolein in novel space groups, P1 and H32. Due to ease of its purification and crystallization OmpF can be used as a benchmark protein for establishing membrane protein crystallization in meso, as a "membrane lyzozyme". The packing of porin trimers in the crystals of space group H32 is similar to natural outer membranes, providing the first high-resolution insight into the close to native packing of OmpF. Surprisingly, interaction between trimers is mediated exclusively by lipids, without direct protein-protein contacts. Multiple ordered lipids are observed and many of them occupy identical positions independently of the space group, identifying preferential interaction sites of lipid acyl chains. Presence of ordered aliphatic chains close to a positively charged area on the porin surface suggests a position for a lipopolysaccharide binding site on the surface of the major E. coli porins.

PubMed: 22484237
DOI: 10.1016/j.jsb.2012.03.005

Experimental method

X-RAY DIFFRACTION (1.9 Å)