2j58: Difference between revisions

Many types of bacteria produce extracellular polysaccharides (EPSs). Some, are secreted polymers and show only limited association with the cell, surface, whereas others are firmly attached to the cell surface and form a, discrete structural layer, the capsule, which envelopes the cell and, allows the bacteria to evade or counteract the host immune system. EPSs, have critical roles in bacterial colonization of surfaces, such as, epithelia and medical implants; in addition some EPSs have important, industrial and biomedical applications in their own right. Here we, describe the 2.26 A resolution structure of the 340 kDa octamer of Wza, an, integral outer membrane lipoprotein, which is essential for group 1, capsule export in Escherichia coli. The transmembrane region is a novel, alpha-helical barrel. The bulk of the Wza structure is located in the, periplasm and comprises three novel domains forming a large central, cavity. Wza is open to the extracellular environment but closed to the, periplasm. We propose a route and mechanism for translocation of the, capsular polysaccharide. This work may provide insight into the export of, other large polar molecules such as DNA and proteins.

2J58 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4, OCT and HEX as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2J58 OCA].  

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