Open AccessHigh‐resolution diffraction from crystals of a membrane‐protein complex: bacterial outer membrane protein OmpC complexed with the antibacterial eukaryotic protein lactoferrin
Author(s) -
Sundara Baalaji N.,
Acharya K. Ravi,
Singh T. P.,
Krishnaswamy S.
Publication year - 2005
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309105022086
Subject(s) - lactoferrin , bacterial outer membrane , membrane protein , chemistry , membrane , vesicle associated membrane protein 8 , protein crystallization , resolution (logic) , materials science , biophysics , crystallography , biochemistry , biology , escherichia coli , crystallization , gene , organic chemistry , artificial intelligence , computer science
Crystals of the complex formed between the outer membrane protein OmpC from Escherichia coli and the eukaryotic antibacterial protein lactoferrin from Camelus dromedarius (camel) have been obtained using a detergent environment. Initial data processing suggests that the crystals belong to the hexagonal space group P 6, with unit‐cell parameters a = b = 116.3, c = 152.4 Å, α = β = 90, γ = 120°. This indicated a Matthews coefficient ( V M ) of 3.3 Å 3 Da −1 , corresponding to a possible molecular complex involving four molecules of lactoferrin and two porin trimers in the unit cell (4832 amino acids; 533.8 kDa) with 63% solvent content. A complete set of diffraction data was collected to 3 Å resolution at 100 K. Structure determination by molecular replacement is in progress. Structural study of this first surface‐exposed membrane‐protein complex with an antibacterial protein will provide insights into the mechanism of action of OmpC as well as lactoferrin.