9U5N | pdb_00009u5n

Structure of Chloroflexus aggregans flavin based fluorescent protein (CagFbFP) Q89E variant (complex with FMN)

PDB DOI: https://doi.org/10.2210/pdb9U5N/pdb

Classification: FLUORESCENT PROTEIN
Organism(s): Chloroflexus aggregans DSM 9485
Expression System: Escherichia coli
Mutation(s): Yes

Deposited: 2025-03-21 Released: 2026-03-25
Deposition Author(s): Nikolaev, A., Markeeva, E., Kovalev, K., Gushchin, I.
Funding Organization(s): Not funded

Experimental Data Snapshot

Method: X-RAY DIFFRACTION
Resolution: 1.27 Å
R-Value Free:
0.189 (Depositor), 0.190 (DCC)
R-Value Work:
0.160 (Depositor), 0.160 (DCC)

Starting Model: experimental
View more details

wwPDB Validation 3D Report Full Report

Ligand Structure Quality Assessment

This is version 1.0 of the entry. See complete history.

Literature

Discovery of excited state proton transfer in flavin-based fluorescent protein with large Stokes shift

Nikolaev, A., Markeeva, E.

To be published.

Macromolecule Content

Total Structure Weight: 25.91 kDa
Atom Count: 1,964
Modeled Residue Count: 211
Deposited Residue Count: 226
Unique protein chains: 1

Macromolecules

Find similar proteins by:

(by identity cutoff) | 3D Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
histidine kinase	A, B	113	Chloroflexus aggregans DSM 9485	Mutation(s): 2 Gene Names: Cagg_3753 EC: 2.7.13.3
UniProt
Find proteins for B8GAY9 (Chloroflexus aggregans (strain MD-66 / DSM 9485)) Explore B8GAY9 Go to UniProtKB: B8GAY9
Entity Groups
Sequence Clusters	30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt Group	B8GAY9
Sequence Annotations Expand
Reference Sequence

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
FMN (Subject of Investigation/LOI) Query on FMN Download Ideal Coordinates CCD File SDF format, chain D [auth A] SDF format, chain E [auth B] MOL2 format, chain D [auth A] MOL2 format, chain E [auth B] mmCIF format, chain D [auth A] mmCIF format, chain E [auth B]	D [auth A], E [auth B]	FLAVIN MONONUCLEOTIDE C₁₇ H₂₁ N₄ O₉ P FVTCRASFADXXNN-SCRDCRAPSA-N		Interactions Focus chain D [auth A] Focus chain E [auth B] Interactions & Density Focus chain D [auth A] Focus chain E [auth B]
MES Query on MES Download Ideal Coordinates CCD File SDF format, chain C [auth A] MOL2 format, chain C [auth A] mmCIF format, chain C [auth A]	C [auth A]	2-(N-MORPHOLINO)-ETHANESULFONIC ACID C₆ H₁₃ N O₄ S SXGZJKUKBWWHRA-UHFFFAOYSA-N		Interactions Focus chain C [auth A] Interactions & Density Focus chain C [auth A]

Experimental Data & Validation

Experimental Data

Method: X-RAY DIFFRACTION
Resolution: 1.27 Å
R-Value Free: 0.189 (Depositor), 0.190 (DCC)
R-Value Work: 0.160 (Depositor), 0.160 (DCC)

Space Group: P 2₁ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 53.722	α = 90
b = 109.602	β = 90
c = 39.053	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
XDS	data reduction
Aimless	data scaling
MOLREP	phasing

Structure Validation

View Full Validation Report

Ligand Structure Quality Assessment

Entry History & Funding Information

Deposition Data

Released Date: 2026-03-25

Deposition Author(s):

Funding Organization	Location	Grant Number
Not funded		--

Revision History (Full details and data files)

Version 1.0: 2026-03-25
Type: Initial release

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.