Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 9.44 kDa 
• Atom Count: 667 
• Modelled Residue Count: 76 
• Deposited Residue Count: 78 
• Unique protein chains: 1

 1TIF

TRANSLATION INITIATION FACTOR 3 N-TERMINAL DOMAIN

• PDB DOI: 10.2210/pdb1TIF/pdb

• Classification: RIBOSOME BINDING FACTOR
• Organism(s): Geobacillus stearothermophilus
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1995-08-16 Released: 1995-12-07 
• Deposition Author(s): Biou, V., Shu, F., Ramakrishnan, V.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.233 
• R-Value Work: 0.192 
• R-Value Observed: 0.192 

Literature

X-ray crystallography shows that translational initiation factor IF3 consists of two compact alpha/beta domains linked by an alpha-helix.

Biou, V., Shu, F., Ramakrishnan, V.

(1995) EMBO J 14: 4056-4064

• PubMed: 7664745 
• DOI: 10.1002/j.1460-2075.1995.tb00077.x
• Primary Citation of Related Structures:  
  1TIF, 1TIG


• PubMed Abstract: 
  

The structures of the two domains of translational initiation factor IF3 from Bacillus stearothermophilus have been solved by X-ray crystallography using single wavelength anomalous scattering and multiwavelength anomalous diffraction. Each of the two domains has an alpha/beta topology, with an exposed beta-sheet that is reminiscent of several ribosomal and other RNA binding proteins. An alpha-helix that protrudes out from the body of the N-terminal domain towards the C-terminal domain suggests that IF3 consists of two RNA binding domains connected by an alpha-helix and that it may bridge two regions of the ribosome. This represents the first high resolution structural information on a translational initiation factor.

---

Related Citations: 

• Prokaryotic Translation Initiation Factor If3 is an Elongated Protein Consisting of Two Crystallizable Domains
  Kycia, J.H., Biou, V., Shu, F., Gerchman, S.E., Graziano, V., Ramakrishnan, V.
  (1995) Biochemistry 34: 6183

---

Organizational Affiliation: 

Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TRANSLATION INITIATION FACTOR 3	A	78	Geobacillus stearothermophilus	Mutation(s): 0  Gene Names: T7, infC
UniProt
Find proteins for P03000 (Geobacillus stearothermophilus) Explore P03000  Go to UniProtKB:  P03000

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PBM	B [auth A]	TRIMETHYL LEAD ION C3 H9 Pb SNBFOEGVGALPSE-UHFFFAOYSA-N
CL	C [auth A], 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: 0.233 
• R-Value Work: 0.192 
• R-Value Observed: 0.192 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 27.6	α = 90
b = 39.2	β = 90
c = 65.9	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
MOSFLM	data reduction
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1995-12-07 
Deposition Author(s): Biou, V., Shu, F., Ramakrishnan, V.

Revision History  

• Version 1.0: 1995-12-07
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance