1SLI

LEECH INTRAMOLECULAR TRANS-SIALIDASE COMPLEXED WITH DANA

• PDB DOI: https://doi.org/10.2210/pdb1SLI/pdb

• Classification: HYDROLASE
• Organism(s): Macrobdella decora
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 1998-03-28 Released: 1999-04-20 
• Deposition Author(s): Luo, Y., Li, S.C., Chou, M.Y., Li, Y.T., Luo, M.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.224 
• R-Value Work: 0.167 
• R-Value Observed: 0.167 

Literature

The crystal structure of an intramolecular trans-sialidase with a NeuAc alpha2-->3Gal specificity.

Luo, Y., Li, S.C., Chou, M.Y., Li, Y.T., Luo, M.

(1998) Structure 6: 521-530

• PubMed: 9562562 
• DOI: https://doi.org/10.1016/s0969-2126(98)00053-7
• Primary Citation of Related Structures:  
  1SLI, 1SLL


• PubMed Abstract: 
  

  Intramolecular trans-sialidase from leech (Macrobdella decora) is a unique enzyme which cleaves the terminal neuraminic acid (NeuAc) residue from sialoglycoconjugates, releasing 2, 7-anhydro-neuraminic acid (2,7-anhydro-NeuAc). It is the first enzyme found to exhibit strictly specific cleavage of NeuAc alpha2-->3Gal linkages in sialoglycoconjugates. The release of 2,7-anhydro-NeuAc instead of NeuAc implies a unique mechanism, in which the sialosyl linkage is transferred within the sialoglycoconjugate rather than hydrolyzed. The aims of the structural study were to gain structural insight into the strict specificity and unique mechanism of this unusual enzyme.

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Organizational Affiliation: 

Center for Macromolecular Crystallography, University of Alabama at Birmingham, Alabama 35294, USA.

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 74.86 kDa 
• Atom Count: 5,894 
• Modelled Residue Count: 679 
• Deposited Residue Count: 679 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
INTRAMOLECULAR TRANS-SIALIDASE	A	679	Macrobdella decora	Mutation(s): 0  Gene Names: T7 EC: 3.2.1.18
UniProt
Find proteins for Q27701 (Macrobdella decora) Explore Q27701  Go to UniProtKB:  Q27701

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
DAN	B [auth A]	2-DEOXY-2,3-DEHYDRO-N-ACETYL-NEURAMINIC ACID C11 H17 N O8 JINJZWSZQKHCIP-UFGQHTETSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Free: 0.224 
• R-Value Work: 0.167 
• R-Value Observed: 0.167 
• Space Group: P 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 46.443	α = 113.14
b = 69.516	β = 95.39
c = 72.514	γ = 106.87

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

• Released Date: 1999-04-20 
Deposition Author(s): Luo, Y., Li, S.C., Chou, M.Y., Li, Y.T., Luo, M.

Revision History  

• Version 1.0: 1999-04-20
  Type: Initial release
  
• Version 1.1: 2008-03-03
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2020-07-29
  Type: Remediation
  Reason: Carbohydrate remediation
  Changes: Data collection, Derived calculations, Other
• Version 1.4: 2024-02-14
  Changes: Data collection, Database references, Structure summary
• Version 1.5: 2024-04-03
  Changes: Refinement description