4p5f

Publication Abstract from PubMed

Effector proteins are virulence factors that promote pathogenesis by interfering with various cellular events and are delivered directly into host cells by the secretion systems of many Gram-negative bacteria. Type III effector protein XOO4466 from the plant pathogen Xanthomonas oryzae pv. oryzae (XopQXoo ) and XopQ homologs from other phytopathogens have been predicted to be nucleoside hydrolases based on their sequence similarities. However, despite such similarities, recent structural and functional studies have revealed that XopQXoo does not exhibit the expected activity of a nucleoside hydrolase. On the basis of the conservation of a Ca2+ coordination shell of a ribose-binding site and the spacious active site in XopQXoo , we hypothesized that a novel compound containing a ribosyl moiety could serve as a substrate for XopQXoo . Here, we report the crystal structure of XopQXoo in complex with adenosine diphosphate ribose (ADPR), which is involved in regulating cytoplasmic Ca2+ concentrations in eukaryotic cells. ADPR is bound to the active site of XopQXoo with its ribosyl end tethered to the Ca2+ coordination shell. The binding of ADPR is further stabilized by interactions mediated by hydrophobic residues that undergo ligand-induced conformational changes. These data showed that XopQXoo is capable of binding a novel chemical bearing a ribosyl moiety, thereby providing the first step toward understanding the functional role of XopQXoo . Proteins 2014. (c) 2014 Wiley Periodicals, Inc.

The crystal structure of type III effector protein XopQ from Xanthomonas oryzae complexed with adenosine diphosphate ribose.,Yu S, Hwang I, Rhee S Proteins. 2014 Jul 31. doi: 10.1002/prot.24656. PMID:25079351^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.