1w3a: Difference between revisions

LSL is a lectin produced by the parasitic mushroom Laetiporus sulphureus, which exhibits hemolytic and hemagglutinating activities. Here, we report, the crystal structure of LSL refined to 2.6-A resolution determined by the, single isomorphous replacement method with the anomalous scatter (SIRAS), signal of a platinum derivative. The structure reveals that LSL is, hexameric, which was also shown by analytical ultracentrifugation. The, monomeric protein (35 kDa) consists of two distinct modules: an N-terminal, lectin module and a pore-forming module. The lectin module has a, beta-trefoil scaffold that bears structural similarities to those present, in toxins known to interact with galactose-related carbohydrates such as, the hemagglutinin component (HA1) of the progenitor toxin from Clostridium, botulinum, abrin, and ricin. On the other hand, the C-terminal, pore-forming module (composed of domains 2 and 3) exhibits, three-dimensional structural resemblances with domains 3 and 4 of the, beta-pore-forming toxin aerolysin from the Gram-negative bacterium, Aeromonas hydrophila, and domains 2 and 3 from the epsilon-toxin from, Clostridium perfringens. This finding reveals the existence of common, structural elements within the aerolysin-like family of toxins that could, be directly involved in membrane-pore formation. The crystal structures of, the complexes of LSL with lactose and N-acetyllactosamine reveal two, dissacharide-binding sites per subunit and permits the identification of, critical residues involved in sugar binding.

1W3A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Laetiporus_sulphureus Laetiporus sulphureus] with LBT and GOL 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=1W3A OCA].  

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