Biological Assembly 1  

 3D View: Structure | Ligand Interaction

Global Symmetry: Dihedral - D2  (3D View)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 26.09 kDa 
• Atom Count: 1557 
• Modelled Residue Count: 194 
• Deposited Residue Count: 236 
• Unique protein chains: 1

1R94

Crystal Structure of IscA (MERCURY DERIVATIVE)

• DOI: 10.2210/pdb1R94/pdb

• Classification: METAL TRANSPORT
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2003-10-28 Released: 2003-12-23 
• Deposition Author(s): Bilder, P.W., Ding, H., Newcomer, M.E.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Free: 0.263 
• R-Value Work: 0.229 
• R-Value Observed: 0.231 

Literature

Crystal structure of the ancient, Fe-S scaffold IscA reveals a novel protein fold.

Bilder, P.W., Ding, H., Newcomer, M.E.

(2004) Biochemistry 43: 133-139

• PubMed: 14705938 
• DOI: 10.1021/bi035440s
• Primary Citation of Related Structures:  
  1R95, 1R94


• PubMed Abstract: 
  

IscA belongs to an ancient family of proteins responsible for iron-sulfur cluster assembly in essential metabolic pathways preserved throughout evolution. We report here the 2.3 A resolution crystal structure of Escherichia coli IscA, a novel fold in which mixed beta-sheets form a compact alpha-beta sandwich domain. In contrast to the highly mobile secondary structural elements within the bacterial Fe-S scaffold protein IscU, a protein which is thought to have a similar function, the great majority of the amino acids that are conserved in IscA homologues are located in elements that constitute a well-ordered fold. However, the 10-residue C-terminal tail segment that contains two invariant cysteines critical for the Fe-S-binding function of a cyanobacterial (Synechocystis PCC) IscA homologue is not ordered in our structure. In addition, the crystal packing reveals a helical assembly that is constructed from two possible tetrameric oligomers of IscA.

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Organizational Affiliation: 

Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Protein yfhF	A, B	118	Escherichia coli	Mutation(s): 0  Gene Names: yfhF, b2528, C3053, Z3795, ECS3394, SF2575, S2747
Find proteins for P0AAC8 (Escherichia coli (strain K12)) Explore P0AAC8  Go to UniProtKB:  P0AAC8

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HG	C [auth A], D [auth B]	MERCURY (II) ION Hg BQPIGGFYSBELGY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.30 Å
• R-Value Free: 0.263 
• R-Value Work: 0.229 
• R-Value Observed: 0.231 
• Space Group: P 6₂

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 55.337	α = 90
b = 55.337	β = 90
c = 159.835	γ = 120

Software Package:

Software Name	Purpose
REFMAC	refinement
MAR345	data collection
SCALEPACK	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-10-28 
• Released Date: 2003-12-23 
Deposition Author(s): Bilder, P.W., Ding, H., Newcomer, M.E.

Revision History  

• Version 1.0: 2003-12-23
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2017-10-11
  Changes: Refinement description