Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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

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

Biological Assembly 2  

 3D View: Structure | Electron Density | Ligand Interaction

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

Biological assembly 2 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 106.19 kDa 
• Atom Count: 7611 
• Residue Count: 913 
• Unique protein chains: 1

1QWJ

The Crystal Structure of Murine CMP-5-N-Acetylneuraminic Acid Synthetase

• DOI: 10.2210/pdb1QWJ/pdb

• Classification: TRANSFERASE
• Organism(s): Mus musculus
• Expression System: Escherichia coli BL21
• Mutation(s): No 


• Deposited: 2003-09-02 Released: 2003-12-09 
• Deposition Author(s): Krapp, S., Muenster-Kuehnel, A.K., Kaiser, J.T., Huber, R., Tiralongo, J., Gerardy-Schahn, R., Jacob, U.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.304 
• R-Value Work: 0.240 

Literature

The Crystal Structure of Murine CMP-5-N-acetylneuraminic Acid Synthetase

Krapp, S., Muenster-Kuehnel, A.K., Kaiser, J.T., Huber, R., Tiralongo, J., Gerardy-Schahn, R., Jacob, U.

(2003) J Mol Biol 334: 625-637

• PubMed: 14636592 
• DOI: 10.1016/j.jmb.2003.09.080
• Primary Citation of Related Structures:  
  1QWJ


• PubMed Abstract: 
  

Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase prior to their transfer onto oligo- or polysaccharides. Here, we present the crystal structure of the N-terminal catalytically active domain of the murine 5-N-acetylneuraminic acid synthetase in complex with the reaction product. In contrast to the previously solved structure of 5-N-acetylneuraminic acid synthetase from Neisseria meningitidis and the related CMP-KDO-synthetase of Escherichia coli, the murine enzyme is a tetramer, which was observed with the active sites closed. In this conformation a loop is shifted by 6A towards the active site and thus an essential arginine residue can participate in catalysis. Furthermore, a network of intermolecular salt-bridges and hydrogen bonds in the dimer as well as hydrophobic interfaces between two dimers indicate a cooperative behaviour of the enzyme. In addition, a complex regulation of the enzyme activity is proposed that includes phosphorylation and dephosphorylation.

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Organizational Affiliation: 

Max-Planck-Institut für Biochemie, Abteilung für Strukturforschung, Am Klopferspitz 18a, 82152, Martinsried, Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
cytidine monophospho-N-acetylneuraminic acid synthetase	A, B, C, D	229	Mus musculus	Mutation(s): 0  Gene Names: Cmas EC: 2.7.7.43
Find proteins for Q99KK2 (Mus musculus) Explore Q99KK2  Go to UniProtKB:  Q99KK2

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NCC	A, C, D	CYTIDINE-5'-MONOPHOSPHATE-5-N-ACETYLNEURAMINIC ACID C20 H31 N4 O16 P TXCIAUNLDRJGJZ-BILDWYJOSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.304 
• R-Value Work: 0.240 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 74.048	α = 90
b = 79.941	β = 90
c = 170.251	γ = 90

Software Package:

Software Name	Purpose
MOSFLM	data reduction
SCALA	data scaling
CNS	refinement
CCP4	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-09-02 
• Released Date: 2003-12-09 
Deposition Author(s): Krapp, S., Muenster-Kuehnel, A.K., Kaiser, J.T., Huber, R., Tiralongo, J., Gerardy-Schahn, R., Jacob, U.

Revision History 

• Version 1.0: 2003-12-09
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance