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1zld
From Proteopedia
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Crystal structure of a RGD-containing host-selective toxin: Pyrenophora tritici-repentis Ptr ToxA
Overview
Tan spot of wheat (Triticum aestivum), caused by the fungus Pyrenophora, tritici-repentis, has significant agricultural and economic impact. Ptr, ToxA (ToxA), the first discovered proteinaceous host-selective toxin, is, produced by certain P. tritici-repentis races and is necessary and, sufficient to cause cell death in sensitive wheat cultivars. We present, here the high-resolution crystal structure of ToxA in two different, crystal forms, providing four independent views of the protein. ToxA, adopts a single-domain, beta-sandwich fold of novel topology. Mapping of, the existing mutation data onto the structure supports the hypothesized, importance of an Arg-Gly-Asp (RGD) and surrounding sequence. Its, occurrence in a single, solvent-exposed loop in the protein suggests that, it is directly involved in recognition events required for ToxA action., Furthermore, the ToxA structure reveals a surprising similarity with the, classic mammalian RGD-containing domain, the fibronectin type III (FnIII), domain: the two topologies are related by circular permutation. The, similar topologies and the positional conservation of the RGD-containing, loop raises the possibility that ToxA is distantly related to mammalian, FnIII proteins and that to gain entry it binds to an integrin-like, receptor in the plant host.
About this Structure
1ZLD is a Single protein structure of sequence from Pyrenophora tritici-repentis with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of Ptr ToxA: an RGD-containing host-selective toxin from Pyrenophora tritici-repentis., Sarma GN, Manning VA, Ciuffetti LM, Karplus PA, Plant Cell. 2005 Nov;17(11):3190-202. Epub 2005 Oct 7. PMID:16214901
Page seeded by OCA on Tue Jan 29 17:37:23 2008
