PDBsum entry 7bwc

Hydrolase

PDB id: 7bwc

Contents

Protein chain

464 a.a.

Ligands

GLC-FRU

Waters ×144

PDB id:

7bwc

Name:

Hydrolase

Title:

Bombyx mori gh32 beta-fructofuranosidase bmsuc1 mutant d63a in complex with sucrose

Structure:

Beta-fructofuranosidase. Chain: a. Engineered: yes. Mutation: yes. Other_details: the sequence is registered genbank with an accession code of bcd57653

Source:

Bombyx mori. Silk moth. Organism_taxid: 7091. Gene: bmsuc1, suc1. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.95Å R-factor: 0.216 R-free: 0.247

Authors:

T.Miyazaki,N.Oba

Key ref:

T.Miyazaki et al. (2020). Structural insight into the substrate specificity of Bombyx mori β-fructofuranosidase belonging to the glycoside hydrolase family 32. Insect Biochem Mol Biol, 127, 103494. PubMed id: 33132139 DOI: 10.1016/j.ibmb.2020.103494

Date:

14-Apr-20 Release date: 04-Nov-20

Protein chain

A0A6F8Z6Y2  (A0A6F8Z6Y2_BOMMO) -  Sucrose-6-phosphate hydrolase from Bombyx mori

Seq: 488 a.a.

Struc: 464 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

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.

DOI no: 10.1016/j.ibmb.2020.103494

Insect Biochem Mol Biol 127:103494 (2020)

PubMed id: 33132139

Structural insight into the substrate specificity of Bombyx mori β-fructofuranosidase belonging to the glycoside hydrolase family 32.

T.Miyazaki, N.Oba, E.Y.Park.

ABSTRACT

Sucrose-hydrolyzing enzymes are largely divided into β-fructofuranosidase and sucrose α-glucosidase. The domestic silkworm Bombyx mori possesses both enzymes, BmSUC1 and BmSUH, belonging to the glycoside hydrolase family 32 (GH32) and GH13, respectively. BmSUC1 was presumed to be acquired by horizontal gene transfer from bacteria based on phylogenetic analysis and related to tolerance to sugar-mimic alkaloids contained in mulberry latex. Here we investigated the substrate specificity of recombinant BmSUC1 that can hydrolyze not only sucrose but also fructooligosaccharides and fructans, and revealed that the enzyme was competitively inhibited by 1,4-dideoxy-1,4-imino-D-arabinitol, one of the alkaloids. Moreover, the crystal structures of BmSUC1 in apo form and complex with sucrose were determined, and the active site pocket was shallow and suitable for shorter substrates but was related to more relaxed substrate specificity than the strict sucrose α-glucosidase BmSUH. Considering together with the distribution of BmSUC1-orthologous genes in many lepidopterans, our results suggest that BmSUC1 contributes to the digestion of fructooligosaccharides and fructans derived from feed plants.