Crystal Structure of Glucansucrase

Experimental Data Snapshot

  • Resolution: 3.09 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.213 

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This is version 2.1 of the entry. See complete history


Crystal structure of glucansucrase from the dental caries pathogen Streptococcus mutans.

Ito, K.Ito, S.Shimamura, T.Weyand, S.Kawarasaki, Y.Misaka, T.Abe, K.Kobayashi, T.Cameron, A.D.Iwata, S.

(2011) J Mol Biol 408: 177-186

  • DOI: https://doi.org/10.1016/j.jmb.2011.02.028
  • Primary Citation of Related Structures:  
    3AIB, 3AIC, 3AIE

  • PubMed Abstract: 

    Glucansucrase (GSase) from Streptococcus mutans is an essential agent in dental caries pathogenesis. Here, we report the crystal structure of S. mutans glycosyltransferase (GTF-SI), which synthesizes soluble and insoluble glucans and is a glycoside hydrolase (GH) family 70 GSase in the free enzyme form and in complex with acarbose and maltose. Resolution of the GTF-SI structure confirmed that the domain order of GTF-SI is circularly permuted as compared to that of GH family 13 α-amylases. As a result, domains A, B and IV of GTF-SI are each composed of two separate polypeptide chains. Structural comparison of GTF-SI and amylosucrase, which is closely related to GH family 13 amylases, indicated that the two enzymes share a similar transglycosylation mechanism via a glycosyl-enzyme intermediate in subsite -1. On the other hand, novel structural features were revealed in subsites +1 and +2 of GTF-SI. Trp517 provided the platform for glycosyl acceptor binding, while Tyr430, Asn481 and Ser589, which are conserved in family 70 enzymes but not in family 13 enzymes, comprised subsite +1. Based on the structure of GTF-SI and amino acid comparison of GTF-SI, GTF-I and GTF-S, Asp593 in GTF-SI appeared to be the most critical point for acceptor sugar orientation, influencing the transglycosylation specificity of GSases, that is, whether they produced insoluble glucan with α(1-3) glycosidic linkages or soluble glucan with α(1-6) linkages. The structural information derived from the current study should be extremely useful in the design of novel inhibitors that prevent the biofilm formation by GTF-SI.

  • Organizational Affiliation

    Department of Food and Nutritional Sciences, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-Ku, Shizuoka 422-8526, Japan. itosohei@u-shizuoka-ken.ac.jp

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Glucosyltransferase-SI844Streptococcus mutansMutation(s): 0 
Gene Names: gtfCSMU_1005
Find proteins for P13470 (Streptococcus mutans serotype c (strain ATCC 700610 / UA159))
Explore P13470 
Go to UniProtKB:  P13470
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP13470
Sequence Annotations
  • Reference Sequence


Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
Glycosylation Resources
GlyTouCan:  G07411ON
GlyCosmos:  G07411ON
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on MES

Download Ideal Coordinates CCD File 
K [auth A]
M [auth B]
O [auth C]
Q [auth D]
S [auth G]
K [auth A],
M [auth B],
O [auth C],
Q [auth D],
S [auth G],
U [auth E],
W [auth F],
Y [auth H]
C6 H13 N O4 S
Query on CA

Download Ideal Coordinates CCD File 
J [auth A]
L [auth B]
N [auth C]
P [auth D]
R [auth G]
J [auth A],
L [auth B],
N [auth C],
P [auth D],
R [auth G],
T [auth E],
V [auth F],
X [auth H]
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Resolution: 3.09 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.213 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 295.42α = 90
b = 213.94β = 90
c = 220.98γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-03-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2013-08-07
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2024-03-13
    Changes: Data collection, Database references, Structure summary