9EGC | pdb_00009egc

AclA from Tenacibaculum discolor in complex with the C8-N-acyl cyclolysine reaction product (C8-ACL)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 
    0.222 (Depositor), 0.222 (DCC) 
  • R-Value Work: 
    0.179 (Depositor), 0.180 (DCC) 
  • R-Value Observed: 
    0.181 (Depositor) 

Starting Model: in silico
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

Discovery of a widespread chemical signalling pathway in the Bacteroidota.

Linares-Otoya, L.Shirkey, J.D.Chhetri, B.K.Mira, A.Biswas, A.Neff, S.L.Linares-Otoya, M.V.Chen, Y.Campos-Florian, J.V.Ganoza-Yupanqui, M.L.Jeffrey, P.D.Hughson, F.M.Donia, M.S.

(2025) Nature 

  • DOI: https://doi.org/10.1038/s41586-025-09418-9
  • Primary Citation of Related Structures:  
    9EGB, 9EGC, 9EGD

  • PubMed Abstract: 

    Considerable advances have been made in characterizing bioactive molecules secreted by bacteria, yet the regulatory elements controlling their production remain largely understudied. Here we identify and characterize the N-acyl-cyclolysine (ACL) system-a cell-density-dependent chemical signalling system specific to and widespread in the phylum Bacteroidota (formerly Bacteroidetes)-and show that it regulates the expression of co-localized operons encoding diverse secreted molecules. Using genetic and biochemical analyses, combined with structural studies of a key biosynthetic enzyme, AclA, we elucidate the molecular structure of various ACLs and their complete biosynthetic pathway involving L-lysine acylation and ATP-dependent cyclization. Furthermore, we find that secreted ACLs are sensed by a dedicated transcription factor, AclR, resulting in the expression of associated operons and the autoinduction of ACL biosynthesis. Moreover, we show that different Bacteroidota strains produce structurally diverse ACLs and encode transcription factors with varying ligand specificities. Finally, we find that the acl circuit is widely distributed and transcribed in human gut and oral microbiome samples, with clear evidence for an active role in regulating associated operons under host colonization conditions. Understanding the function of the ACL system in different contexts has the potential to reveal details about the biology, ecology and chemistry of the Bacteroidota and how members of this phylum interact with their environments and hosts.


  • Organizational Affiliation
    • Department of Molecular Biology, Princeton University, Princeton, NJ, USA.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
THIF-type NAD/FAD binding fold domain-containing protein
A, B, C, D, E
A, B, C, D, E, F, G
264Tenacibaculum discolorMutation(s): 0 
Gene Names: CSC81_02270
UniProt
Find proteins for A0A2G1BYE5 (Tenacibaculum discolor)
Explore A0A2G1BYE5 
Go to UniProtKB:  A0A2G1BYE5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A2G1BYE5
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1CA3 (Subject of Investigation/LOI)
Query on A1CA3

Download Ideal Coordinates CCD File 
H [auth A]
M [auth B]
P [auth C]
R [auth D]
T [auth E]
H [auth A],
M [auth B],
P [auth C],
R [auth D],
T [auth E],
W [auth F],
Y [auth G]
N-[(3R)-2-oxoazepan-3-yl]octanamide
C14 H26 N2 O2
MVDRULJBGMOKJF-UHFFFAOYSA-N
MAE
Query on MAE

Download Ideal Coordinates CCD File 
I [auth A]
N [auth B]
Q [auth C]
S [auth D]
U [auth E]
I [auth A],
N [auth B],
Q [auth C],
S [auth D],
U [auth E],
X [auth F],
Z [auth G]
MALEIC ACID
C4 H4 O4
VZCYOOQTPOCHFL-UPHRSURJSA-N
PEG
Query on PEG

Download Ideal Coordinates CCD File 
J [auth A],
K [auth A],
L [auth A],
O [auth B],
V [auth E]
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free:  0.222 (Depositor), 0.222 (DCC) 
  • R-Value Work:  0.179 (Depositor), 0.180 (DCC) 
  • R-Value Observed: 0.181 (Depositor) 
Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 204.374α = 90
b = 84.36β = 105.61
c = 164.527γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
XDSdata reduction
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United StatesR01AI172144

Revision History  (Full details and data files)

  • Version 1.0: 2025-08-13
    Type: Initial release
  • Version 1.1: 2025-08-20
    Changes: Database references
  • Version 1.2: 2025-09-03
    Changes: Database references