Biological Assembly 1  

 3D View: Structure | Ligand Interaction

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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: 89069.79 
• Atom Count: 4514 
• Residue Count: 840 
• Unique protein chains: 1

2A8M

Crystal Structure of Human Taspase1 (T234S mutant)

• DOI: 10.2210/pdb2A8M/pdb

• Classification: HYDROLASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): 1 


• Deposited: 2005-07-08 Released: 2005-10-25 
• Deposition Author(s): Khan, J.A., Dunn, B.M., Tong, L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.290 
• R-Value Work: 0.207 

Literature

Crystal Structure of Human Taspase1, a Crucial Protease Regulating the Function of MLL.

Khan, J.A., Dunn, B.M., Tong, L.

(2005) Structure 13: 1443-1452

• PubMed: 16216576 
• DOI: 10.1016/j.str.2005.07.006
• Primary Citation of Related Structures:  
  2A8L, 2A8J, 2A8I


• PubMed Abstract: 
  

Taspase1 catalyzes the proteolytic processing of the mixed lineage leukemia (MLL) nuclear protein, which is required for maintaining Hox gene expression patterns. Chromosomal translocations of the MLL gene are associated with leukemia in infants. Taspase1, a threonine aspartase, is a member of the type 2 asparaginase family, but is the only protease in this family. We report here the crystal structures of human activated Taspase1 and its proenzyme, as well as the characterization of the effects of mutations in the active site region using a newly developed fluorogenic assay. The structure of Taspase1 has significant differences from other asparaginases, especially near the active site. Mutation of the catalytic nucleophile, Thr234, abolishes autocatalytic processing in cis but does not completely block proteolysis in trans. The structure unexpectedly showed the binding of a chloride ion in the active site, and our kinetic studies confirm that chlorides ions are inhibitors of this enzyme at physiologically relevant concentrations.

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Organizational Affiliation: 

Department of Biological Sciences, Columbia University, New York, New York 10027, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Threonine aspartase 1	A, B	420	Homo sapiens	Mutation(s): 1  Gene Names: TASP1 (C20orf13) EC: 3.4.25.-
Find proteins for Q9H6P5 (Homo sapiens) Go to Gene View: TASP1 Go to UniProtKB:  Q9H6P5

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
CL	A, B	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.290 
• R-Value Work: 0.207 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length (Å)	Angle (°)
a = 60.441	α = 90.00
b = 89.371	β = 90.00
c = 104.276	γ = 90.00

Software Package:

Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
RESOLVE	phasing
SOLVE	phasing
SnB	phasing
CNS	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2005-07-08 
• Released Date: 2005-10-25 
• Deposition Author(s): Khan, J.A., Dunn, B.M., Tong, L.

Revision History 

• Version 1.0: 2005-10-25
  Type: Initial release
• Version 1.1: 2008-04-30
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance
• Version 1.3: 2017-10-11
  Type: Refinement description