1BB1 | pdb_00001bb1

CRYSTAL STRUCTURE OF A DESIGNED, THERMOSTABLE HETEROTRIMERIC COILED COIL

• PDB DOI: https://doi.org/10.2210/pdb1BB1/pdb

• Classification: DE NOVO PROTEIN DESIGN
• Organism(s): synthetic construct
• Mutation(s): No 


• Deposited: 1998-04-28 Released: 1999-02-02 
• Deposition Author(s): Nautiyal, S., Alber, T.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 
  0.269 (Depositor) 
• R-Value Work: 
  0.208 (Depositor) 
• R-Value Observed: 
  0.208 (Depositor) 

Literature

Crystal structure of a designed, thermostable, heterotrimeric coiled coil.

Nautiyal, S., Alber, T.

(1999) Protein Sci 8: 84-90

• PubMed: 10210186 
• DOI: https://doi.org/10.1110/ps.8.1.84
• Primary Citation Related Structures: 
  1BB1


• PubMed Abstract: 
  

  Electrostatic interactions are often critical for determining the specificity of protein-protein complexes. To study the role of electrostatic interactions for assembly of helical bundles, we previously designed a thermostable, heterotrimeric coiled coil, ABC, in which charged residues were employed to drive preferential association of three distinct, 34-residue helices. To investigate the basis for heterotrimer specificity, we have used multiwavelength anomalous diffraction (MAD) analysis to determine the 1.8 A resolution crystal structure of ABC. The structure shows that ABC forms a heterotrimeric coiled coil with the intended arrangement of parallel chains. Over half of the ion pairs engineered to restrict helix associations were apparent in the experimental electron density map. As seen in other trimeric coiled coils, ABC displays acute knobs-into-holes packing and a buried anion coordinated by core polar amino acids. These interactions validate the design strategy and illustrate how packing and polar contacts determine structural uniqueness.

---

Organizational Affiliation: 
• Department of Molecular and Cell Biology, University of California, Berkeley 94720-3206, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 3-mer - A2B1 Pseudo Symmetry: Cyclic - C3  (Explore in 3D)
Pseudo Stoichiometry: Homo 3-mer - A3 

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

Macromolecule Content 

• Total Structure Weight: 11.25 kDa 
• Atom Count: 900 
• Modeled Residue Count: 108 
• Deposited Residue Count: 108 
• Unique protein chains: 3

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
DESIGNED, THERMOSTABLE HETEROTRIMERIC COILED COIL	A	36	synthetic construct	Mutation(s): 0

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
DESIGNED, THERMOSTABLE HETEROTRIMERIC COILED COIL	B	36	synthetic construct	Mutation(s): 0

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
DESIGNED, THERMOSTABLE HETEROTRIMERIC COILED COIL	C	36	synthetic construct	Mutation(s): 0

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CL	D [auth A]	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free:  0.269 (Depositor) 
• R-Value Work:  0.208 (Depositor) 
• R-Value Observed: 0.208 (Depositor) 

Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 21.93	α = 90
b = 35.01	β = 93.7
c = 66.46	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
DENZO	data reduction
CCP4	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1999-02-02 
Deposition Author(s): Nautiyal, S., Alber, T.

Revision History  

• Version 1.0: 1999-02-02
  Type: Initial release
  
• Version 1.1: 2008-03-03
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-06-05
  Changes: Data collection, Database references, Derived calculations, Other
• Version 1.4: 2024-10-16
  Changes: Structure summary