3KLK

Crystal structure of Lactobacillus reuteri N-terminally truncated glucansucrase GTF180 in triclinic apo- form

Summary for 3KLK

• Entry DOI: 10.2210/pdb3klk/pdb
• Related: 3HQ3 3HZ3 3KLL
• Descriptor: Glucansucrase, CALCIUM ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: native form, open conformation, multidomain protein, glycosyltransferase, transferase
• Biological source: Lactobacillus reuteri
• Total number of polymer chains: 1
• Total formula weight: 117512.46

Authors

Vujicic-Zagar, A.,Pijning, T.,Kralj, S.,Eeuwema, W.,Dijkhuizen, L.,Dijkstra, B.W. (deposition date: 2009-11-08, release date: 2010-11-03, Last modification date: 2024-03-20)

Primary citation

Vujicic-Zagar, A.,Pijning, T.,Kralj, S.,Lopez, C.A.,Eeuwema, W.,Dijkhuizen, L.,Dijkstra, B.W.
Crystal structure of a 117 kDa glucansucrase fragment provides insight into evolution and product specificity of GH70 enzymes
Proc.Natl.Acad.Sci.USA, 107:21406-21411, 2010

PubMed Abstract: Glucansucrases are large enzymes belonging to glycoside hydrolase family 70, which catalyze the cleavage of sucrose into fructose and glucose, with the concomitant transfer of the glucose residue to a growing α-glucan polymer. Among others, plaque-forming oral bacteria secrete these enzymes to produce α-glucans, which facilitate the adhesion of the bacteria to the tooth enamel. We determined the crystal structure of a fully active, 1,031-residue fragment encompassing the catalytic and C-terminal domains of GTF180 from Lactobacillus reuteri 180, both in the native state, and in complexes with sucrose and maltose. These structures show that the enzyme has an α-amylase-like (β/α)(8)-barrel catalytic domain that is circularly permuted compared to the catalytic domains of members of glycoside hydrolase families 13 and 77, which belong to the same GH-H superfamily. In contrast to previous suggestions, the enzyme has only one active site and one nucleophilic residue. Surprisingly, in GTF180 the peptide chain follows a "U"-path, such that four of the five domains are made up from discontiguous N- and C-terminal stretches of the peptide chain. Finally, the structures give insight into the factors that determine the different linkage types in the polymeric product.

PubMed: 21118988
DOI: 10.1073/pnas.1007531107

Experimental method

X-RAY DIFFRACTION (1.65 Å)