3tl8
The AvrPtoB-BAK1 complex reveals two structurally similar kinaseinteracting domains in a single type III effector
Structural highlights
FunctionBAK1_ARATH Dual specificity kinase acting on both serine/threonine- and tyrosine-containing substrates. Controls the expression of genes associated with innate immunity in the absence of pathogens or elicitors. Involved in brassinosteroid (BR) signal transduction. Phosphorylates BRI1. May be involved in changing the equilibrium between plasma membrane-located BRI1 homodimers and endocytosed BRI1-BAK1 heterodimers. Interaction with MSBP1 stimulates the endocytosis of BAK1 and suppresses brassinosteroid signaling. Acts in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) via its interaction with FLS2 and the phosphorylation of BIK1. Involved in programmed cell death (PCD) control. Positively regulates the BR-dependent plant growth pathway and negatively regulates the BR-independent cell-death pathway.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedTo infect plants, Pseudomonas syringae pv. tomato delivers approximately 30 type III effector proteins into host cells, many of which interfere with PAMP-triggered immunity (PTI). One effector, AvrPtoB, suppresses PTI using a central domain to bind host BAK1, a kinase that acts with several pattern recognition receptors to activate defense signaling. A second AvrPtoB domain binds and suppresses the PTI-associated kinase Bti9 but is conversely recognized by the protein kinase Pto to activate effector-triggered immunity. We report the crystal structure of the AvrPtoB-BAK1 complex, which revealed structural similarity between these two AvrPtoB domains, suggesting that they arose by intragenic duplication. The BAK1 kinase domain is structurally similar to Pto, and a conserved region within both BAK1 and Pto interacts with AvrPtoB. BAK1 kinase activity is inhibited by AvrPtoB, and mutations at the interaction interface disrupt AvrPtoB virulence activity. These results shed light on a structural mechanism underlying host-pathogen coevolution. Structural Analysis of Pseudomonas syringae AvrPtoB Bound to Host BAK1 Reveals Two Similar Kinase-Interacting Domains in a Type III Effector.,Cheng W, Munkvold KR, Gao H, Mathieu J, Schwizer S, Wang S, Yan YB, Wang J, Martin GB, Chai J Cell Host Microbe. 2011 Dec 15;10(6):616-26. Epub 2011 Dec 8. PMID:22169508[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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