Biological Assembly 1  

 3D View: Structure

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

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

Macromolecule Content

• Total Structure Weight: 28.20 kDa 
• Atom Count: 1923 
• Residue Count: 172 
• Unique protein chains: 1
• Unique nucleic acid chains: 2

1AN4

STRUCTURE AND FUNCTION OF THE B/HLH/Z DOMAIN OF USF

• DOI: 10.2210/pdb1AN4/pdb
• NDB: PDT027

• Classification: TRANSCRIPTION/DNA
• Organism(s): Homo sapiens
• Expression System: Bacteria
• Mutation(s): Yes 


• Deposited: 1997-03-15 Released: 1997-09-17 
• Deposition Author(s): Ferre-D'Amare, A.R., Pognonec, P., Roeder, R.G., Burley, S.K.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.90 Å
• R-Value Work: 0.236 

Literature

Structure and function of the b/HLH/Z domain of USF.

Ferre-D'Amare, A.R., Pognonec, P., Roeder, R.G., Burley, S.K.

(1994) EMBO J 13: 180-189

• PubMed: 8306960 
• Primary Citation of Related Structures:  
  1AN4


• PubMed Abstract: 
  

The basic/helix-loop-helix/leucine zipper (b/HLH/Z) transcription factor upstream stimulatory factor (USF) and its isolated DNA binding domain undergo a random coil to alpha-helix folding transition on recognizing their cognate DNA. The USF b/HLH cocrystal structure resembles the structure of the b/HLH/Z domain of the homologous protein Max and reveals (i) that the truncated, b/HLH DNA binding domain homodimerizes, forming a parallel, left-handed four-helix bundle, and (ii) that the basic region becomes alpha-helical on binding to the major groove of the DNA sequence CACGTG. Hydrodynamic measurements show that the b/HLH/Z DNA binding domain of USF exists as a bivalent homotetramer. This tetramer forms at the USF physiological intranuclear concentration, and depends on the integrity of the leucine zipper motif. The ability to bind simultaneously to two independent sites suggests a role in DNA looping for the b/HLH/Z and Myc-related families of eukaryotic transcription factors.

---

Organizational Affiliation: 

Laboratories of Molecular Biophysics, Rockefeller University, New York, NY 10021.

Macromolecules

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (UPSTREAM STIMULATORY FACTOR)	A, B	65	Homo sapiens	Mutation(s): 2  Gene Names: USF1, BHLHB11, USF
Find proteins for P22415 (Homo sapiens) Explore P22415  Go to UniProtKB:  P22415
NIH Common Fund Data Resources
PHAROS  P22415 GTEx  ENSG00000158773

Entity ID: 1
Molecule	Chains	Length	Organism	Image
DNA (5'-D(*CP*AP*CP*CP*CP*GP*GP*TP*CP*AP*CP*GP*TP*GP*GP*CP*C P*TP*AP*CP*A)-3')	C	21	N/A

Entity ID: 2
Molecule	Chains	Length	Organism	Image
DNA (5'-D(*GP*TP*GP*TP*AP*GP*GP*CP*CP*AP*CP*GP*TP*GP*AP*CP*C P*GP*GP*GP*T)-3')	D	21	N/A

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.90 Å
• R-Value Work: 0.236 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 136.6	α = 90
b = 54.7	β = 90
c = 44.4	γ = 90

Software Package:

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

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1997-03-15 
• Released Date: 1997-09-17 
Deposition Author(s): Ferre-D'Amare, A.R., Pognonec, P., Roeder, R.G., Burley, S.K.

Revision History 

• Version 1.0: 1997-09-17
  Type: Initial release
  
• Version 1.1: 2008-05-22
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2020-02-26
  Changes: Data collection, Database references