PDBsum entry 3rj0

Signaling protein

PDB id: 3rj0

Contents

Protein chain

741 a.a.

Ligands

NAG-NAG-BMA-MAN ×3

NAG ×3

BLD

Waters ×114

PDB id:

3rj0

Name:

Signaling protein

Title:

Plant steroid receptor bri1 ectodomain in complex with brassinolide

Structure:

Protein brassinosteroid insensitive 1. Chain: a. Fragment: ectodomain (unp residues 29-788). Synonym: bri1, brassinosteroid lrr receptor kinase, atbri1. Engineered: yes

Source:

Arabidopsis thaliana. Mouse-ear cress. Organism_taxid: 3702. Gene: at4g39400, bri1, f23k16.30. Expressed in: trichoplusia ni. Expression_system_taxid: 7111.

Resolution:

2.54Å R-factor: 0.187 R-free: 0.241

Authors:

M.Hothorn

Key ref:

M.Hothorn et al. (2011). Structural basis of steroid hormone perception by the receptor kinase BRI1. Nature, 474, 467-471. PubMed id: 21666665

Date:

14-Apr-11 Release date: 22-Jun-11

Protein chain

O22476  (BRI1_ARATH) -  Protein BRASSINOSTEROID INSENSITIVE 1 from Arabidopsis thaliana

Seq: 1196 a.a.

Struc: 741 a.a.

Enzyme reactions

• Enzyme class 2: E.C.2.7.10.1 - receptor protein-tyrosine kinase.
• Reaction: L-tyrosyl-[protein] + ATP = O-phospho-L-tyrosyl-[protein] + ADP + H⁺

L-tyrosyl-[protein] + ATP = O-phospho-L-tyrosyl-[protein] (Bound ligand (Het Group name = NAG) matches with 41.38% similarity) + ADP + H(+)

• Enzyme class 3: E.C.2.7.11.1 - non-specific serine/threonine protein kinase.
• Reaction:
  1. L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H⁺
  2. L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H⁺

L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] (Bound ligand (Het Group name = NAG) matches with 41.38% similarity) + ADP + H(+)

L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] (Bound ligand (Het Group name = NAG) matches with 41.38% similarity) + ADP + H(+)

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

Nature 474:467-471 (2011)

PubMed id: 21666665

Structural basis of steroid hormone perception by the receptor kinase BRI1.

M.Hothorn, Y.Belkhadir, M.Dreux, T.Dabi, J.P.Noel, I.A.Wilson, J.Chory.

ABSTRACT

Polyhydroxylated steroids are regulators of body shape and size in higher organisms. In metazoans, intracellular receptors recognize these molecules. Plants, however, perceive steroids at membranes, using the membrane-integral receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1). Here we report the structure of the Arabidopsis thaliana BRI1 ligand-binding domain, determined by X-ray diffraction at 2.5 Å resolution. We find a superhelix of 25 twisted leucine-rich repeats (LRRs), an architecture that is strikingly different from the assembly of LRRs in animal Toll-like receptors. A 70-amino-acid island domain between LRRs 21 and 22 folds back into the interior of the superhelix to create a surface pocket for binding the plant hormone brassinolide. Known loss- and gain-of-function mutations map closely to the hormone-binding site. We propose that steroid binding to BRI1 generates a docking platform for a co-receptor that is required for receptor activation. Our findings provide insight into the activation mechanism of this highly expanded family of plant receptors that have essential roles in hormone, developmental and innate immunity signalling.