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From Proteopedia
COMPLEX OF HSP90 N-TERMINAL, SGT1 CS AND RAR1 CHORD2 DOMAIN
Structural highlights
Function[RAR1_ARATH] Required specifically for plant innate immunity. Is essential for resistance conferred by multiple R genes recognizing different bacterial and oomycete pathogen isolates like avirulent P.syringae or H.parasitica (downy mildew). Contributes additively with SGT1B to RPP5-dependent resistance. Functions as positive regulator of RPS5 accumulation by assisting its stabilization. May function as co-chaperone of HSP90-2 to positively regulate the steady-state accumulation of RPM1 and protect it from SGT1-mediated degradation. Acts as negative regulator of pathogen-associated molecular pattern (PAMP)-triggered immunity.[1] [2] [3] [4] [5] [6] [7] [8] [SGT1A_ARATH] Functions in R gene-mediated resistance, but participates in a lower extent than SGT1B to RPP5-mediated resistance. Not required for RPM1, RPS2, RPS4 and RPS5-mediated resistance. Probably required for SCF-mediated ubiquitination, by coupling HSP90 to SCF complex for ubiquitination of HSP90 client proteins.[9] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedHsp90-mediated function of NLR receptors in plant and animal innate immunity depends on the cochaperone Sgt1 and, at least in plants, on a cysteine- and histidine-rich domains (CHORD)-containing protein Rar1. Functionally, CHORD domains are associated with CS domains, either within the same protein, as in the mammalian melusin and Chp1, or in separate but interacting proteins, as in the plant Rar1 and Sgt1. Both CHORD and CS domains are independently capable of interacting with the molecular chaperone Hsp90 and can coexist in complexes with Hsp90. We have now determined the structure of an Hsp90-CS-CHORD ternary complex, providing a framework for understanding the dynamic nature of Hsp90-Rar1-Sgt1 complexes. Mutational and biochemical analyses define the architecture of the ternary complex that recruits nucleotide-binding leucine-rich repeat receptors (NLRs) by manipulating the structural elements to control the ATPase-dependent conformational cycle of the chaperone. Structural basis for assembly of Hsp90-Sgt1-CHORD protein complexes: implications for chaperoning of NLR innate immunity receptors.,Zhang M, Kadota Y, Prodromou C, Shirasu K, Pearl LH Mol Cell. 2010 Jul 30;39(2):269-81. PMID:20670895[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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