1QO0 | pdb_00001qo0

Amide receptor of the amidase operon of Pseudomonas aeruginosa (AmiC) complexed with the negative regulator AmiR.

• PDB DOI: https://doi.org/10.2210/pdb1QO0/pdb

• Classification: BINDING PROTEIN
• Organism(s): Pseudomonas aeruginosa
• Expression System: Pseudomonas aeruginosa
• Mutation(s): No 


• Deposited: 1999-10-26 Released: 1999-12-23 
• Deposition Author(s): Pearl, L.H., O'Hara, B.P., Roe, S.M.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.25 Å
• R-Value Free: 
  0.256 (Depositor), 0.251 (DCC) 
• R-Value Work: 
  0.186 (Depositor) 

Starting Model: experimental

Literature

Crystal Structure and Induction Mechanism of Amic-Amir: A Ligand-Regulated Transcription Antitermination Complex

O'Hara, B.P., Norman, R.A., Wan, P.T.C., Roe, S.M., Barrett, T.E., Drew, R.E., Pearl, L.H.

(1999) EMBO J 18: 5175

• PubMed: 10508151 
• DOI: https://doi.org/10.1093/emboj/18.19.5175
• Primary Citation Related Structures: 
  1QO0


• PubMed Abstract: 
  

  Inducible expression of the aliphatic amidase operon in Pseudomonas aeruginosa is controlled by an antitermination mechanism which allows production of the full-length transcript only in the presence of small-molecule inducers, such as acetamide. Ligand-regulated antitermination is provided by AmiC, the ligand-sensitive negative regulator, and AmiR, the RNA-binding positive regulator. Under non-inducing or repressing growth conditions, AmiC and AmiR form a complex in which the activity of AmiR is silenced. The crystal structure of the AmiC-AmiR complex identifies AmiR as a new and highly unusual member of the response-regulator family of bacterial signal transduction proteins, regulated by sequestration rather than phosphorylation. Comparison with the structure of free AmiC reveals the subtle mechanism of ligand-induced release of AmiR.

---

Organizational Affiliation: 
• Centre for Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Hetero 8-mer - A4B4 

Biological assembly 1 generated by PQS (software)

Macromolecule Content 

• Total Structure Weight: 129.9 kDa 
• Atom Count: 9,661 
• Modeled Residue Count: 1,130 
• Deposited Residue Count: 1,162 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
AMIC	A, B	385	Pseudomonas aeruginosa	Mutation(s): 0
UniProt
Find proteins for P27017 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)) Explore P27017  Go to UniProtKB:  P27017

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
AMIR	C [auth D], D [auth E]	196	Pseudomonas aeruginosa	Mutation(s): 0
UniProt
Find proteins for P10932 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)) Explore P10932  Go to UniProtKB:  P10932

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
BMD	E [auth A], F [auth B]	BUTYRAMIDE C4 H9 N O DNSISZSEWVHGLH-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.25 Å
• R-Value Free:  0.256 (Depositor), 0.251 (DCC) 
• R-Value Work:  0.186 (Depositor) 

Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 308.44	α = 90
b = 67.15	β = 103.33
c = 76.41	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
MOSFLM	data reduction
SCALA	data scaling
AMoRE	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1999-12-23 
Deposition Author(s): Pearl, L.H., O'Hara, B.P., Roe, S.M.

Revision History  

• Version 1.0: 1999-12-23
  Type: Initial release
  
• Version 1.1: 2011-05-08
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2019-05-08
  Changes: Data collection, Experimental preparation, Other
• Version 1.4: 2023-12-13
  Changes: Data collection, Database references, Derived calculations, Other, Refinement description