Publication Date:
2015-01-28
Description:
The Bam machinery, which is highly conserved from bacteria to humans, is well recognized as the apparatus responsible for the insertion and folding of most outer membrane proteins in Gram-negative bacteria. InEscherichia coli, the Bam machinery consists of five components (i.e.BamA, BamB, BamC, BamD and BamE). In comparison, there are only four partners inHaemophilus influenzae: a BamB homologue is not found in its genome. In this study, the recombinant expression, purification, crystallization and preliminary X-ray diffraction analysis ofH. influenzaeBamD and BamCD complex are reported. The genes encoding BamC and BamD were cloned into a pET vector and expressed inE. coli. Affinity, ion-exchange and gel-filtration chromatography were used to obtain high-purity protein for further crystallographic characterization. Using the hanging-drop vapour-diffusion technique, BamD and BamCD protein crystals of suitable size were obtained using protein concentrations of 70 and 50 mg ml−1, respectively. Preliminary X-ray diffraction analysis showed that the BamD crystals diffracted to 4.0 Å resolution and belonged to space groupP212121, with unit-cell parametersa= 54.5,b= 130.5,c= 154.7 Å. The BamCD crystals diffracted to 3.8 Å resolution and belonged to space groupI212121, with unit-cell parametersa= 101.6,b= 114.1,c= 234.9 Å.
Electronic ISSN:
2053-230X
Topics:
Biology
,
Chemistry and Pharmacology
,
Geosciences
,
Physics
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