PDBsum entry 2ncg

Unknown function

PDB id: 2ncg

Contents

Protein chain

118 a.a.

PDB id:

2ncg

Name:

Unknown function

Title:

The cc domain structure from the wheat stem rust resistance protein sr33 challenges paradigms for dimerization in plant nlr proteins

Structure:

Rga1e. Chain: a. Fragment: coiled-coil domain residues 6-120. Engineered: yes

Source:

Aegilops tauschii. Tausch's goatgrass. Organism_taxid: 37682. Gene: sr33. Expressed in: escherichia coli. Expression_system_taxid: 511693.

NMR struc:

20 models

Authors:

P.Lavrencic,M.Mobli

Key ref:

L.W.Casey et al. (2016). The CC domain structure from the wheat stem rust resistance protein Sr33 challenges paradigms for dimerization in plant NLR proteins. Proc Natl Acad Sci U S A, 113, 12856-12861. PubMed id: 27791121 DOI: 10.1073/pnas.1609922113

Date:

30-Mar-16 Release date: 19-Oct-16

Protein chain

S5DMB1  (S5DMB1_AEGTA) -  RGA1e from Aegilops tauschii

Seq: 961 a.a.

Struc: 118 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1073/pnas.1609922113

Proc Natl Acad Sci U S A 113:12856-12861 (2016)

PubMed id: 27791121

The CC domain structure from the wheat stem rust resistance protein Sr33 challenges paradigms for dimerization in plant NLR proteins.

L.W.Casey, P.Lavrencic, A.R.Bentham, S.Cesari, D.J.Ericsson, T.Croll, D.Turk, P.A.Anderson, A.E.Mark, P.N.Dodds, M.Mobli, B.Kobe, S.J.Williams.

ABSTRACT

Plants use intracellular immunity receptors, known as nucleotide-binding oligomerization domain-like receptors (NLRs), to recognize specific pathogen effector proteins and induce immune responses. These proteins provide resistance to many of the world's most destructive plant pathogens, yet we have a limited understanding of the molecular mechanisms that lead to defense signaling. We examined the wheat NLR protein, Sr33, which is responsible for strain-specific resistance to the wheat stem rust pathogen, Puccinia graminis f. sp. tritici We present the solution structure of a coiled-coil (CC) fragment from Sr33, which adopts a four-helix bundle conformation. Unexpectedly, this structure differs from the published dimeric crystal structure of the equivalent region from the orthologous barley powdery mildew resistance protein, MLA10, but is similar to the structure of the distantly related potato NLR protein, Rx. We demonstrate that these regions are, in fact, largely monomeric and adopt similar folds in solution in all three proteins, suggesting that the CC domains from plant NLRs adopt a conserved fold. However, larger C-terminal fragments of Sr33 and MLA10 can self-associate both in vitro and in planta, and this self-association correlates with their cell death signaling activity. The minimal region of the CC domain required for both cell death signaling and self-association extends to amino acid 142, thus including 22 residues absent from previous biochemical and structural protein studies. These data suggest that self-association of the minimal CC domain is necessary for signaling but is likely to involve a different structural basis than previously suggested by the MLA10 crystallographic dimer.