Abstract
External polysaccharide capsules provide a physical barrier that is employed by many species of bacteria for the purposes of host evasion and persistence. Wzi is a 53 kDa outer membrane β-barrel protein that is thought to play a role in the attachment of group 1 capsular polysaccharides to the cell surface. The purification and crystallization of an Escherichia coli homologue of Wzi is reported and diffraction data from native and selenomethionine-incorporated protein crystals are presented. Crystals of C-terminally His6-tagged Wzi diffracted to 2.8 Å resolution. Data processing showed that the crystals belonged to the orthorhombic space group C222, with unit-cell parameters a=128.8, b=152.8, c=94.4 Å, α=β=γ=90°. A His-tagged selenomethionine-containing variant of Wzi has also been crystallized in the same space group and diffraction data have been recorded to 3.8 Å resolution. Data processing shows that the variant crystal has similar unit-cell parameters to the native crystal.
Highlights
Extracellular polysaccharide capsules are produced by many species of bacteria to provide protection from the environment
The capsule primarily consists of long chains of repeat-unit polysaccharides that are firmly attached to the bacterial outer membrane by processes that are frequently not understood
Data processing showed that the native crystals belonged to the orthorhombic space group C222, with unit-cell parameters a = 128.8, b = 152.8, c = 94.4 A, = = = 90
Summary
Extracellular polysaccharide capsules are produced by many species of bacteria to provide protection from the environment. Wzi is not essential for CPS synthesis (Drummelsmith & Whitfield, 1999); wzi knockouts in both E. coli and Klebsiella spp. doi:10.1107/S1744309110040546 1621 crystallization communications (which use virtually identical Wzi, Wza, Wzb and Wzc proteins; Rahn et al, 1999) show a profoundly altered morphology of the capsule (Alvarez et al, 2000; Rahn et al, 2003). Doi:10.1107/S1744309110040546 1621 crystallization communications (which use virtually identical Wzi, Wza, Wzb and Wzc proteins; Rahn et al, 1999) show a profoundly altered morphology of the capsule (Alvarez et al, 2000; Rahn et al, 2003) This is the result of a markedly increased secretion of unattached exopolysaccharide into the environment and a commensurate decrease in attached CPS (Alvarez et al, 2000; Rahn et al, 2003). We describe the purification and crystallization of recombinant Wzi and report on the progress of crystallographic diffraction studies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
