G1UH28 · CHIT_PUNGR

Function

function

Hydrolyzes chitin. Probable calcium storage protein of the seeds. Binds calcium ions with high capacity and low affinity. Involved in seed germination.

Catalytic activity

  • Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1->4)-beta-linkages in chitin and chitodextrins.
    EC:3.2.1.14 (UniProtKB | ENZYME | Rhea)

Activity regulation

Activity is not affected by addition of 10 mM Ca2+ or removal of Ca2+.

Kinetics

kcat/KM is 0.119 M-1sec-1 for native protein, 0.130 M-1sec-1 for native protein with 10 mM Ca2+ and 0.116 M-1sec-1 for EDTA-treated protein, using 4-methylumbelliferyl-beta-D-N,N',N''-triacetylchitotrioside (4-MU(GlcNAc)3) as substrate at pH 4.5 and 37 degrees Celsius.

pH Dependence

Optimum pH is between 2.5 and 5.0. Removal of Ca2+ from the protein by EDTA treatment narrows the pH range to 2.5-3.5.

Temperature Dependence

Optimum temperature is approximately 45 degrees Celsius. Removal of Ca2+ from the protein by EDTA treatment decreases the optimum temperature to 35 degrees Celsius.

Features

Showing features for active site.

TypeIDPosition(s)Description
Active site153Proton donor

GO annotations

AspectTerm
Cellular Componentamyloplast
Molecular Functioncalcium ion binding
Molecular Functionchitinase activity
Biological Processchitin catabolic process
Biological Processpolysaccharide catabolic process
Biological Processseed germination
Biological Processseedling development

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Acidic endochitinase Pun g 14, amyloplastic
  • EC number
  • Alternative names
    • Chitinase III
    • Pomegranate seed chitinase
  • Allergen name
    Pun g 14

Gene names

    • Name
      PSC
    • ORF names
      CDL15_Pgr011527

Organism names

  • Taxonomic identifier
  • Strain
    • cv. Dabenzi
  • Taxonomic lineage
    Eukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > malvids > Myrtales > Lythraceae > Punica

Accessions

  • Primary accession
    G1UH28

Proteomes

Subcellular Location

Plastid, amyloplast
Note: Localizes to stroma in amyloplasts of the embryonic cells of the seed.

Keywords

Phenotypes & Variants

Allergenic properties

Causes an allergic reaction in human. Binds to IgE in 19% of 357 patients allergic to pomegranate.

Keywords

Protein family/group databases

PTM/Processing

Features

Showing features for transit peptide, chain, disulfide bond.

TypeIDPosition(s)Description
Transit peptide1-26Amyloplast
ChainPRO_501120658127-299Acidic endochitinase Pun g 14, amyloplastic
Disulfide bond46↔93
Disulfide bond76↔83
Disulfide bond185↔216

Keywords

Expression

Tissue specificity

Highly expressed in seeds and to a lesser extent in the skin of the pomegranate fruit (at protein level). Not expressed in leaves or flesh of the fruit (at protein level).

Developmental stage

Expressed at all stages of seed germination. Expression decreases markedly from day 1 to day 15 after imbibition.

Interaction

Subunit

Monomer.

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain27-299GH18

Sequence similarities

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    299
  • Mass (Da)
    31,747
  • Last updated
    2011-11-16 v1
  • Checksum
    D5D28157AA92D0B1
MAKTLPFSRALLLSLSILLVARAISAGDIAIYWGQNGGEGTLASTCDTGRYAYVIVSFVTTFGNFRAPVVNLAGHCDPAAGTCTGLSDEIRSCQGKDIKVLMSIGGGAGDYSLVSEADADNFADYLWNNFLGGQSSSRPLGDAVLDGIDFDIELGTTTFYDTLARALSSRSTQAAKVYLTAAPQCPHPDSHLDAALNTGLFDNVWIQFYNNPLAQCQYSSGNTNDILSSWNTWTSSTTAGKIFLGLPAAPEAAGSGYIPPDVLTGQILPQIKTSAKYGGVMLYSKFYDTTYSTTIKDQV

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict90in Ref. 1; AA sequence
Sequence conflict295in Ref. 1; AA sequence

Mass Spectrometry

Molecular mass is 29,008.7 Da. Determined by MALDI. The measured mass is that of EDTA-treated protein to remove Ca(2+).
Molecular mass is 29,389.8 Da. Determined by MALDI. The measured mass is that of protein without EDTA-treatment to retain Ca(2+).
Molecular mass is 29,001.76 Da. Determined by MALDI. The measured mass is that of protein with three disulfide bridges.

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AB605773
EMBL· GenBank· DDBJ
BAK68869.1
EMBL· GenBank· DDBJ
mRNA
MTKT01005817
EMBL· GenBank· DDBJ
OWM64072.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

Disclaimer

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