Crystal Structure of E.Coli Branching Enzyme in complex with maltohexaose

Experimental Data Snapshot

  • Resolution: 2.55 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.183 

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Crystal Structures of Escherichia coli Branching Enzyme in Complex with Linear Oligosaccharides.

Feng, L.Fawaz, R.Hovde, S.Gilbert, L.Chiou, J.Geiger, J.H.

(2015) Biochemistry 54: 6207-6218

  • DOI: https://doi.org/10.1021/acs.biochem.5b00228
  • Primary Citation of Related Structures:  
    4LPC, 4LQ1

  • PubMed Abstract: 

    Branching enzyme is responsible for all branching of glycogen and starch. It is an unusual member of the α-amylase family because it has both α-1,4-amylase activity and α-1,6-transferase activity [Drummond, G. S., et al. (1972) Eur. J. Biochem. 26, 168-176]. It also does not react with shorter glucans, though it will bind much longer substrates and substrate mimics [Binderup, K., et al. (2002) Arch. Biochem. Biophys. 397, 279-285]. In an effort to better understand how branching enzyme interacts with its polymeric substrate, we have determined the structure of Δ112 Escherichia coli branching enzyme bound to maltoheptaose and maltohexaose. Together, these structures define six distinct oligosaccharide binding sites on the surface of E. coli branching enzyme. Most of these binding sites surround the edge of the β-barrel domain and are quite far from the active site. Surprisingly, there is no evidence of oligosaccharide binding in the active site of the enzyme. The closest bound oligosaccharide resides almost 18 Å from the active site. Mutations to conserved residues in binding sites I and VI had a debilitating effect on the activity of the enzyme.

  • Organizational Affiliation

    Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
1,4-alpha-glucan branching enzyme GlgB
A, B, C, D
612Escherichia coliMutation(s): 0 
Gene Names: glgBb3432JW3395
Find proteins for P07762 (Escherichia coli (strain K12))
Explore P07762 
Go to UniProtKB:  P07762
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP07762
Sequence Annotations
  • Reference Sequence


Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
E, F, G, H, I
Glycosylation Resources
GlyTouCan:  G07411ON
GlyCosmos:  G07411ON
Experimental Data & Validation

Experimental Data

  • Resolution: 2.55 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.183 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 93.694α = 90
b = 104.113β = 91.85
c = 186.712γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
HKL-2000data collection

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-04-01
    Type: Initial release
  • Version 1.1: 2015-09-23
    Changes: Database references
  • Version 1.2: 2016-04-06
    Changes: Database references
  • Version 1.3: 2017-11-15
    Changes: Refinement description
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2024-02-28
    Changes: Data collection, Database references, Structure summary