PDBsum entry: 1uyp

Hydrolase

PDB id: 1uyp

Contents

Protein chains

(+ 0 more) 432 a.a. *

Ligands

SO4 ×14

CIT

GOL ×6

Metals

_NA

Waters ×1756

* Residue conservation analysis

PDB id:

1uyp

Name:

Hydrolase

Title:

The three-dimensional structure of beta-fructosidase (invertase) from thermotoga maritima

Structure:

Beta-fructosidase. Chain: a, b, c, d, e, f. Engineered: yes

Source:

Thermotoga maritima. Organism_taxid: 243274. Strain: msb8. Expressed in: escherichia coli. Expression_system_taxid: 511693. Other_details: german collection of microorganisms (dsm 3109)

Resolution:

1.90Å R-factor: 0.179 R-free: 0.220

Authors:

F.Alberto,C.Bignon,G.Sulzenbacher,B.Henrissat,M.Czjzek

Key ref:

F.Alberto et al. (2004). The three-dimensional structure of invertase (beta-fructosidase) from Thermotoga maritima reveals a bimodular arrangement and an evolutionary relationship between retaining and inverting glycosidases. J Biol Chem, 279, 18903-18910. PubMed id: 14973124 DOI: 10.1074/jbc.M313911200

Date:

02-Mar-04 Release date: 22-Mar-04

Supersedes:

1utw

Protein chains

O33833  (BFRA_THEMA) -  Beta-fructosidase

Seq: 432 a.a.

Struc: 432 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.2.1.26 - Beta-fructofuranosidase.
• Reaction: Hydrolysis of terminal non-reducing beta-D-fructofuranoside residues in beta-D-fructofuranosides.

 Gene Ontology (GO) functional annotation 

• Biological process: metabolic process (2 terms)
• Biochemical function: hydrolase activity (4 terms)

DOI no: 10.1074/jbc.M313911200

J Biol Chem 279:18903-18910 (2004)

PubMed id: 14973124

The three-dimensional structure of invertase (beta-fructosidase) from Thermotoga maritima reveals a bimodular arrangement and an evolutionary relationship between retaining and inverting glycosidases.

F.Alberto, C.Bignon, G.Sulzenbacher, B.Henrissat, M.Czjzek.

ABSTRACT

Thermotoga maritima invertase (beta-fructosidase) hydrolyzes sucrose to release fructose and glucose, which are major carbon and energy sources for both prokaryotes and eukaryotes. The name "invertase" was given to this enzyme over a century ago, because the 1:1 mixture of glucose and fructose that it produces was named "invert sugar." Despite its name, the enzyme operates with a mechanism leading to the retention of the anomeric configuration at the site of cleavage. The enzyme belongs to family GH32 of the sequence-based classification of glycosidases. The crystal structure, determined at 2-A resolution, reveals two modules, namely a five-bladed beta-propeller with structural similarity to the beta-propeller structures of glycosidase from families GH43 and GH68 connected to a beta-sandwich module. Three carboxylates at the bottom of a deep, negatively charged funnel-shaped depression of the beta-propeller are essential for catalysis and function as nucleophile, general acid, and transition state stabilizer, respectively. The catalytic machinery of invertase is perfectly superimposable to that of the enzymes of families GH43 and GH68. The variation in the position of the furanose ring at the site of cleavage explains the different mechanisms evident in families GH32 and GH68 (retaining) and GH43 (inverting) furanosidases.

Selected figure(s)

Figure 4.
FIG. 4. Structural comparison of families GH32, GH68, and GH43. A, structural superimposition of the three strictly conserved residues in the catalytic sites of T. maritima invertase (magenta), Bacillus subtilis levansucrase (dark blue) and Cellvibrio japonicus -L-arabinanase (yellow). B, stereographic view of the superimposed catalytic active sites of -L-arabinanase (yellow) in complex with arabinotriose (orange; Protein Data Bank identification 1GYE [PDB] ), and invertase (dark purple) in complex with the modeled sucrose molecule (blue). The different binding modes of the two enzymes lead to a different position of the glycosidic bond with respect to the catalytic machinery. The anomeric carbons at the point of cleavage of both substrate molecules are colored red. The loops, including residues Trp-41 and Trp-14, which define the -1 subsite in invertase, are either not present or are displaced in -L-arabinanase. In contrast, the loop containing Phe-114, which encloses the substrate in the binding cleft in -L-arabinanase, is absent in invertase. Single letter amino acid abbreviations are used with position numbers.

Figure 5.
FIG. 5. The C-terminal -sandwich module. A, ribbon representation of residues 306-432 of T. maritima invertase displaying the -sandwich fold with colors ranging from blue at the N-terminal end to red at the C-terminal end. B, comparison of A to the structure of human galectin-3 (Protein Data Bank identification 1A3K [PDB] ) in approximately the same orientation, highlighting the similarity of the two structures.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2004, 279, 18903-18910) copyright 2004.

Figures were selected by the author.