9KAI | pdb_00009kai

Crystal Structure of Chalcone Isomerase-like Protein from Physcomitrella patens

• PDB DOI: https://doi.org/10.2210/pdb9KAI/pdb

• Classification: TRANSFERASE
• Organism(s): Physcomitrium patens
• Expression System: Escherichia coli BL21
• Mutation(s): No 


• Deposited: 2024-10-28 Released: 2025-10-29 
• Deposition Author(s): Imaizumi, R., Waki, T., Yasuda, A., Yanai, T., Takeshita, K., Sakai, N., Yamamoto, M., Nakayama, T., Yamashita, S.
• Funding Organization(s): Japan Society for the Promotion of Science (JSPS), Japan Agency for Medical Research and Development (AMED)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.87 Å
• R-Value Free: 
  0.230 (Depositor), 0.230 (DCC) 
• R-Value Work: 
  0.188 (Depositor), 0.188 (DCC) 
• R-Value Observed: 
  0.190 (Depositor) 

Starting Model: experimental

Literature

Transient dynamics of flavonoid metabolons tune chalcone synthase specificity

Imaizumi, R., Waki, T., Hattori, Y., Takeshita, K., Sumita, M., Kawaguchi, K., Kumeta, H., Umeda, K., Sato, K., Yanai, T., Matsuura, H., Yokoyama, T., Omura, R., Nakatani, K., Sakai, N., Kawagiwa, Y., Doi, Y., Yasuda, A., Nakano, T., Uno, K., Yoshida, K., Tsunashima, M., Saio, T., Tanaka, Y., Takahashi, S., Kodera, N., Kataoka, K., Yamamoto, M., Yamashita, S., Nakayama, T.

(2026) Nat Catal 9: 630-644

• DOI: https://doi.org/10.1038/s41929-026-01551-6

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: gel filtration

Macromolecule Content 

• Total Structure Weight: 25.66 kDa 
• Atom Count: 1,790 
• Modeled Residue Count: 206 
• Deposited Residue Count: 228 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Chalcone-flavonone isomerase family protein	A	228	Physcomitrium patens	Mutation(s): 0  Gene Names: PHYPA_006757
UniProt
Find proteins for A9SRW1 (Physcomitrium patens) Explore A9SRW1  Go to UniProtKB:  A9SRW1

Small Molecules

Ligands 4 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
TRS	D [auth A]	2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL C4 H12 N O3 LENZDBCJOHFCAS-UHFFFAOYSA-O
PEG	C [auth A]	DI(HYDROXYETHYL)ETHER C4 H10 O3 MTHSVFCYNBDYFN-UHFFFAOYSA-N
EDO	B [auth A]	1,2-ETHANEDIOL C2 H6 O2 LYCAIKOWRPUZTN-UHFFFAOYSA-N
MG	E [auth A], F [auth A]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.87 Å
• R-Value Free:  0.230 (Depositor), 0.230 (DCC) 
• R-Value Work:  0.188 (Depositor), 0.188 (DCC) 
• R-Value Observed: 0.190 (Depositor) 

Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 61.54	α = 90
b = 45.87	β = 113.229
c = 76.35	γ = 90

Software Package:

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

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2025-10-29 
Deposition Author(s): Imaizumi, R., Waki, T., Yasuda, A., Yanai, T., Takeshita, K., Sakai, N., Yamamoto, M., Nakayama, T., Yamashita, S.

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Funding Organization	Location	Grant Number
Japan Society for the Promotion of Science (JSPS)	Japan	23H05470
Japan Society for the Promotion of Science (JSPS)	Japan	21H02115
Japan Society for the Promotion of Science (JSPS)	Japan	24K23286
Japan Agency for Medical Research and Development (AMED)	Japan	JP20am0101070

Revision History  

• Version 1.0: 2025-10-29
  Type: Initial release
  
• Version 1.1: 2026-11-11
  Changes: Database references