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Transferase PDB id
2q6v
Jmol
Contents
Protein chain
370 a.a. *
Ligands
UDP
Waters ×421
* Residue conservation analysis
PDB id:
2q6v
Name: Transferase
Title: Crystal structure of gumk in complex with udp
Structure: Glucuronosyltransferase gumk. Chain: a. Engineered: yes
Source: Xanthomonas campestris pv. Campestris. Gene: gumk. Expressed in: escherichia coli.
Resolution:
2.28Å     R-factor:   0.177     R-free:   0.216
Authors: M.Barreras
Key ref:
M.Barreras et al. (2008). Structure and mechanism of GumK, a membrane-associated glucuronosyltransferase. J Biol Chem, 283, 25027-25035. PubMed id: 18596046 DOI: 10.1074/jbc.M801227200
Date:
05-Jun-07     Release date:   10-Jun-08    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
Q8GCH2  (Q8GCH2_XANCP) -  UDP-glucuronate:glycolipid 2-beta-glucuronosyltransferase
Seq:
Struc: 		400 a.a.
370 a.a.*
Key:    PfamA domain  Secondary structure
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: E.C.2.4.1.264  - D-man-alpha-(1->3)-D-Glc-beta-(1->4)-D-Glc-alpha-1-diphosphoundecaprenol
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: UDP-glucuronate + D-Man-alpha-(1->3)-D-Glc-beta-(1->4)-D-Glc-alpha-1- diphospho-ditrans,octacis-undecaprenol = UDP + D-GlcA-beta-(1->2)-D-Man- alpha-(1->3)-D-Glc-beta-(1->4)-D-Glc-alpha-1-diphospho-ditrans,octacis- undecaprenol
UDP-glucuronate
Bound ligand (Het Group name = UDP)
matches with 67.00% similarity 		+ D-Man-alpha-(1->3)-D-Glc-beta-(1->4)-D-Glc-alpha-1- diphospho-ditrans,octacis-undecaprenol
 = UDP
 + D-GlcA-beta-(1->2)-D-Man- alpha-(1->3)-D-Glc-beta-(1->4)-D-Glc-alpha-1-diphospho-ditrans,octacis- undecaprenol
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     membrane   2 terms 
  Biological process     carbohydrate metabolic process   2 terms 
  Biochemical function     transferase activity     3 terms  

 

 
    Added reference    
 
 
DOI no: 10.1074/jbc.M801227200 J Biol Chem 283:25027-25035 (2008)
PubMed id: 18596046  
 
 
Structure and mechanism of GumK, a membrane-associated glucuronosyltransferase.
M.Barreras, S.R.Salinas, P.L.Abdian, M.A.Kampel, L.Ielpi.
 
  ABSTRACT  
 
Xanthomonas campestris GumK (beta-1,2-glucuronosyltransferase) is a 44-kDa membrane-associated protein that is involved in the biosynthesis of xanthan, an exopolysaccharide crucial for this bacterium's phytopathogenicity. Xanthan also has many important industrial applications. The GumK enzyme is the founding member of the glycosyltransferase family 70 of carbohydrate-active enzymes, which is composed of bacterial glycosyltransferases involved in exopolysaccharide synthesis. No x-ray structures have been reported for this family. To better understand the mechanism of action of the bacterial glycosyltransferases in this family, the x-ray crystal structure of apo-GumK was solved at 1.9 angstroms resolution. The enzyme has two well defined Rossmann domains with a catalytic cleft between them, which is a typical feature of the glycosyltransferase B superfamily. Additionally, the crystal structure of GumK complexed with UDP was solved at 2.28 angstroms resolution. We identified a number of catalytically important residues, including Asp157, which serves as the general base in the transfer reaction. Residues Met231, Met273, Glu272, Tyr292, Met306, Lys307, and Gln310 interact with UDP, and mutation of these residues affected protein activity both in vitro and in vivo. The biological and structural data reported here shed light on the molecular basis for donor and acceptor selectivity in this glycosyltransferase family. These results also provide a rationale to obtain new polysaccharides by varying residues in the conserved alpha/beta/alpha structural motif of GumK.
 
  Selected figure(s)  
 
Figure 1.
FIGURE 1. Xanthan pentasaccharidic subunit. The formation of the β-1,2-glycosidic bond catalyzed by GumK is shown. 		Figure 7.
FIGURE 7. Proposed catalytic mechanism of GumK. Asp^157 serves as the general base. Residues Lys^307, Met^306, and Tyr^292 that interact with UDP phosphates are depicted in blue.
 
  The above figures are reprinted by permission from the ASBMB: J Biol Chem (2008, 283, 25027-25035) copyright 2008.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
20400947 A.L.Lovering, L.Y.Lin, E.W.Sewell, T.Spreter, E.D.Brown, and N.C.Strynadka (2010).
Structure of the bacterial teichoic acid polymerase TagF provides insights into membrane association and catalysis.
  Nat Struct Mol Biol, 17, 582-589.
PDB codes: 3l7i 3l7j 3l7k 3l7l 3l7m
20581859 B.H.Rehm (2010).
Bacterial polymers: biosynthesis, modifications and applications.
  Nat Rev Microbiol, 8, 578-592.  
19520856 M.E.Guerin, F.Schaeffer, A.Chaffotte, P.Gest, D.Giganti, J.Korduláková, M.van der Woerd, M.Jackson, and P.M.Alzari (2009).
Substrate-induced conformational changes in the essential peripheral membrane-associated mannosyltransferase PimA from mycobacteria: implications for catalysis.
  J Biol Chem, 284, 21613-21625.  
19472250 P.Wang, W.Zhang, J.Zhan, and Y.Tang (2009).
Identification of OxyE as an ancillary oxygenase during tetracycline biosynthesis.
  Chembiochem, 10, 1544-1550.  
18822375 B.Henrissat, G.Sulzenbacher, and Y.Bourne (2008).
Glycosyltransferases, glycoside hydrolases: surprise, surprise!
  Curr Opin Struct Biol, 18, 527-533.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB codes are shown on the right.