PROSITE documentation PDOC50940
Chitin-binding type-2 domain profile


The species distribution of the chitin-binding type-2 domain is complementary to the chitin-binding type-1 domain (see <PDOC00025>). The type-2 is mainly found in animal and baculovirus proteins while the type-1 is found in plant and fungi. Type-2 is characterized by having a 6-cysteine motif: C-x(13,20)-C-x(5,6)-C-x(9,19)-C-x(10,14)-C-x(4,14)-C and several aromatic residues [1].

The structure of the chitin-binding domain of tachycitin has been solved (see <PDB:1DQC>) [2]. It revealed that tachycitin shares a remarkable structural similarity with the chitin-binding type-1 domain of hevein. The overall structure forms a distorted β-sandwich constructed by three-stranded and two-stranded β-sheets connected through a bending loop (Cys-40-Leu-44). The precise chitin binding site (Cys-40 to Gly-60) is perfectly superposable with the chitin binding site of hevein. Furthermore a disulfide bridge connecting Cys-40 and Cys-53 is also present at the same location in the hevein structure [2].

Some protein known to contain a chitin-binding type-2 domain are listed below:

  • Animal class-II chitinase. It degrades chitin and chitotriose. In mammals it may participate in the defense against nematodes and other pathogens [3].
  • Tachycitin, an antimicrobial protein of horseshoe crab hemocytes.
  • Peritrophin-A, a component of peritrophic matrices (acellular linings in the gut of most insects that comprise proteins and sugar polymers, including chitin).
  • Drosophila Tequila protein, a serine protease involved in immune response.
  • Drosophila Hemolectin, a sugar binding protein involved in defense response.

The profile we developed covers the whole domain.

Last update:

July 2016 / Profile revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

CHIT_BIND_II, PS50940; Chitin-binding type-2 domain profile  (MATRIX)


1AuthorsGaines P.J. Walmsley S.J. Wisnewski N.
TitleCloning and characterization of five cDNAs encoding peritrophin-A domains from the cat flea, Ctenocephalides felis.
SourceInsect Biochem. Mol. Biol. 33:1061-1073(2003).
PubMed ID14563358

2AuthorsSuetake T. Tsuda S. Kawabata S. Miura K. Iwanaga S. Hikichi K. Nitta K. Kawano K.
TitleChitin-binding proteins in invertebrates and plants comprise a common chitin-binding structural motif.
SourceJ. Biol. Chem. 275:17929-17932(2000).
PubMed ID10770921

3AuthorsTjoelker L.W. Gosting L. Frey S. Hunter C.L. Trong H.L. Steiner B. Brammer H. Gray P.W.
TitleStructural and functional definition of the human chitinase chitin-binding domain.
SourceJ. Biol. Chem. 275:514-520(2000).
PubMed ID10617646

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