Open AccessCrystallization and preliminary X‐ray diffraction analysis of CfaE, the adhesive subunit of the CFA/I fimbriae from human enterotoxigenic Escherichia coli
Author(s) -
Li YongFu,
Poole Steven,
Rasulova Fatima,
Esser Lothar,
Savarino Stephen J.,
Xia Di
Publication year - 2006
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309105043198
Subject(s) - fimbria , enterotoxigenic escherichia coli , crystallization , protein subunit , microbiology and biotechnology , materials science , crystallography , chemistry , escherichia coli , biology , biochemistry , gene , organic chemistry , enterotoxin
Enterotoxigenic Escherichia coli (ETEC) represents a formidable food and waterborne diarrheal disease threat of global importance. The first step in ETEC pathogenesis is bacterial attachment to small‐intestine epithelial cells via adhesive fimbriae, many of which are genetically related to the prototype colonization factor antigen I (CFA/I). The minor fimbrial subunit CfaE is required for initiation of CFA/I fimbrial assembly and mediates bacterial attachment to host cell‐surface receptors. A donor‐strand complemented variant of CfaE (dscCfaE) was expressed with a hexahistidine tag, purified to homogeneity and crystallized using the hanging‐drop vapor‐diffusion method. X‐ray diffraction data sets were collected to 2.4 Å resolution for both native and derivatized crystals and showed the symmetry of space group P 6 2 22, with unit‐cell parameters a = b = 142.9, c = 231.9 Å. Initial phases were derived from the SIRAS approach and electron density showed two molecules in the crystallographic asymmetric unit. Sequence assignments were aided by anomalous signals from the selenium of an SeMet‐derivatized crystal and from S atoms of a native crystal.