PDBsum entry 4toq

Hydrolase

PDB id: 4toq

Contents

Protein chains

273 a.a.

Metals

_CL ×6

_MG ×13

Waters ×1272

PDB id:

4toq

Name:

Hydrolase

Title:

Crystal structure of class iii chitinase from pomegranate provides the insight into its metal storage capacity

Structure:

Class iii chitinase. Chain: a, b, c, d. Fragment: unp residues 27-299. Engineered: yes

Source:

Punica granatum. Pomegranate. Organism_taxid: 22663. Gene: psc. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.60Å R-factor: 0.157 R-free: 0.192

Authors:

T.Masuda,G.Zhao,B.Mikami

Key ref:

T.Masuda et al. (2015). Crystal structure of class III chitinase from pomegranate provides the insight into its metal storage capacity. Biosci Biotechnol Biochem, 79, 45-50. PubMed id: 25252615 DOI: 10.1080/09168451.2014.962475

Date:

06-Jun-14 Release date: 10-Sep-14

Protein chains

G1UH28  (G1UH28_PUNGR) -  Acidic endochitinase Pun g 14, amyloplastic from Punica granatum

Seq: 299 a.a.

Struc: 273 a.a.

Enzyme reactions

• Enzyme class: E.C.3.2.1.14 - chitinase.
• Reaction: Hydrolysis of the 1,4-beta-linkages of N-acetyl-D-glucosamine polymers of chitin.

DOI no: 10.1080/09168451.2014.962475

Biosci Biotechnol Biochem 79:45-50 (2015)

PubMed id: 25252615

Crystal structure of class III chitinase from pomegranate provides the insight into its metal storage capacity.

T.Masuda, G.Zhao, B.Mikami.

ABSTRACT

Chitinase hydrolyzes the β-1,4-glycosidic bond in chitin. In higher plants, this enzyme has been regarded as a pathogenesis-related protein. Recently, we identified a class III chitinase, which functions as a calcium storage protein in pomegranate (Punica granatum) seed (PSC, pomegranate seed chitinase). Here, we solved a crystal structure of PSC at 1.6 Å resolution. Although its overall structure, including the structure of catalytic site and non-proline cis-peptides, was closely similar to those of other class III chitinases, PSC had some unique structural characteristics. First, there were some metal-binding sites with coordinated water molecules on the surface of PSC. Second, many unconserved aspartate residues were present in the PSC sequence which rendered the surface of PSC negatively charged. This acidic electrostatic property is in contrast to that of hevamine, well-characterized plant class III chitinase, which has rather a positively charged surface. Thus, the crystal structure provides a clue for metal association property of PSC.