8TMX | pdb_00008tmx

Crystal structure of engineered Castilleja foliolosa KAI2d15 variant

• PDB DOI: https://doi.org/10.2210/pdb8TMX/pdb

• Classification: HYDROLASE
• Organism(s): Castilleja foliolosa
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2023-07-31 Released: 2024-12-11 
• Deposition Author(s): Burger, M., Chory, J.
• Funding Organization(s): Howard Hughes Medical Institute (HHMI), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 
  0.256 (Depositor), 0.257 (DCC) 
• R-Value Work: 
  0.205 (Depositor), 0.207 (DCC) 
• R-Value Observed: 
  0.208 (Depositor) 

Starting Model: experimental

Literature

Strigolactones initiate the formation of haustorium-like structures in Castilleja .

Burger, M., Peterson, D., Chory, J.

(2024) iScience 27: 111491-111491

• PubMed: 39759020 
• DOI: https://doi.org/10.1016/j.isci.2024.111491
• Primary Citation Related Structures: 
  8TMX


• PubMed Abstract: 
  

  Strigolactones serve as germination signals for several root-parasitic plant species within the Orobanchaceae family. Yet, their role in the life cycle of the facultatively parasitic genus Castilleja has remained elusive. Here, we demonstrate that strigolactones initiate the formation of haustorium-like structures in Castilleja . We present the genome of Castilleja foliolosa , which reveals an abundance of KAI2d paralogs that act as strigolactone receptors. Castilleja foliolosa 's KAI2d proteins include high-turnover enzymes, in particular KAI2d15, which features a substrate binding pocket with a methionine cluster at its entrance that is involved in the trade-off between substrate turnover and affinity. Our findings provide insights into strigolactone perception in Castilleja and refine our perspective on their role in facultative parasitism.

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Organizational Affiliation: 
• Plant Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Howard Hughes Medical Institute, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 60.54 kDa 
• Atom Count: 4,612 
• Modeled Residue Count: 536 
• Deposited Residue Count: 540 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
KAI2d15	A, B	270	Castilleja foliolosa	Mutation(s): 0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GOL	C [auth A], D [auth A], E [auth B], F [auth B]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free:  0.256 (Depositor), 0.257 (DCC) 
• R-Value Work:  0.205 (Depositor), 0.207 (DCC) 
• R-Value Observed: 0.208 (Depositor) 

Space Group: P 2₁ 2 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 59.576	α = 90
b = 69.537	β = 90
c = 156.563	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
PHENIX	refinement
XDS	data reduction
XSCALE	data scaling
PHASER	phasing

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2024-12-11 
Deposition Author(s): Burger, M., Chory, J.

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Funding Organization	Location	Grant Number
Howard Hughes Medical Institute (HHMI)	United States	--
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	GM122604

Revision History  

• Version 1.0: 2024-12-11
  Type: Initial release
  
• Version 1.1: 2025-01-22
  Changes: Database references