PDBsum entry: 1i75

Transferase

PDB id: 1i75

Contents

Protein chains

686 a.a. *

Ligands

NOJ ×4

Metals

_CA ×4

Waters ×590

* Residue conservation analysis

PDB id:

1i75

Name:

Transferase

Title:

Crystal structure of cyclodextrin glucanotransferase from al bacillus sp.#1011 complexed with 1-deoxynojirimycin

Structure:

Cyclodextrin glucanotransferase. Chain: a, b. Engineered: yes

Source:

Bacillus sp.. Organism_taxid: 1409. Gene: baccgta. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.00Å R-factor: 0.154 R-free: 0.214

Authors:

R.Kanai,K.Haga,K.Yamane,K.Harata

Key ref:

R.Kanai et al. (2001). Crystal structure of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011 complexed with 1-deoxynojirimycin at 2.0 A resolution. J Biochem (tokyo), 129, 593-598. PubMed id: 11275559

Date:

08-Mar-01 Release date: 11-Apr-01

Protein chains

P05618  (CDGT_BACS0) -  Cyclomaltodextrin glucanotransferase

Seq: 713 a.a.

Struc: 686 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.2.4.1.19 - Cyclomaltodextrin glucanotransferase.
• Reaction: Degrades starch to cyclodextrins by formation of a 1,4-alpha-D- glucosidic bond.

 Gene Ontology (GO) functional annotation 

• Cellular component: extracellular region (1 term)
• Biological process: carbohydrate metabolic process (1 term)
• Biochemical function: catalytic activity (9 terms)

J Biochem (tokyo) 129:593-598 (2001)

PubMed id: 11275559

Crystal structure of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011 complexed with 1-deoxynojirimycin at 2.0 A resolution.

R.Kanai, K.Haga, K.Yamane, K.Harata.

ABSTRACT

1-Deoxynojirimycin, a pseudo-monosaccharide, is a strong inhibitor of glucoamylase but a relatively weak inhibitor of cyclodextrin glucanotransferase (CGTase). To elucidate this difference, the crystal structure of the CGTase from alkalophilic Bacillus sp. 1011 complexed with 1-deoxynojirimycin was determined at 2.0 A resolution with the crystallographic R value of 0.154 (R(free) = 0.214). The asymmetric unit of the crystal contains two CGTase molecules and each molecule binds two 1-deoxynojirimycins. One 1-deoxynojirimycin molecule is bound to the active center by hydrogen bonds with catalytic residues and water molecules, but its binding mode differs from that expected in the substrate binding. Another 1-deoxynojirimycin found at the maltose-binding site 1 is bound to Asn-667 with a hydrogen bond and by stacking interaction with the indole moiety of Trp-662 of molecule 1 or Trp-616 of molecule 2. Comparison of this structure with that of the acarbose-CGTase complex suggested that the lack of stacking interaction with the aromatic side chain of Tyr-100 is responsible for the weak inhibition by 1-deoxynojirimycin of the enzymatic action of CGTase.