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Glycoside hydrolase family 19

From Wikipedia, the free encyclopedia
Glycosyl hydrolases family 19
the refined crystal structure of an endochitinase from hordeum vulgare l. seeds to 1.8 angstroms resolution
Identifiers
SymbolGlyco_hydro_19
PfamPF00182
Pfam clanCL0037
InterProIPR000726
PROSITEPDOC00620
SCOP22baa / SCOPe / SUPFAM
CAZyGH19
CDDcd00325
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

In molecular biology, Glycoside hydrolase family 19 is a family of glycoside hydrolases EC 3.2.1., which are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families.[1][2][3] This classification is available on the CAZy web site,[4][5] and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.[6][7] y[ _]9

Glycoside hydrolase family 19 CAZY GH_19 comprises enzymes with only one known activity; chitinase (EC 3.2.1.14).

Chitinases[8] are enzymes that catalyze the hydrolysis of the beta-1,4-N-acetyl-D-glucosamine linkages in chitin polymers. Chitinases belong to glycoside hydrolase families 18 or 19.[9] Chitinases of family 19 (also known as classes IA or I and IB or II) are enzymes from plants that function in the defence against fungal and insect pathogens by destroying their chitin-containing cell wall. Class IA/I and IB/II enzymes differ in the presence (IA/I) or absence (IB/II) of a N-terminal chitin-binding domain. The catalytic domain of these enzymes consist of about 220 to 230 amino acid residues.

Active site

[edit]
Active site of gycoside hydrolase family 19 papaya chitinase (PDB: 3cql​).[10] Conserved residues are shown surrounding the catalytic acid, Glu67. A GlcNAc2 unit binding in the -1 and +1 subsites is shown in narrow stick representation and an arrow indicates the position of the glycosidic oxygen.

GH19 enzymes has a conserved sequence motif ([FHY]-G-R-G-[AP]-ζ-Q-[IL]-[ST]-[FHYW]-[HN]-[FY]-[NY], ζ= hydrophilic amino acid) in its active site.[11]

References

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  1. ^ Henrissat B, Callebaut I, Fabrega S, Lehn P, Mornon JP, Davies G (July 1995). "Conserved catalytic machinery and the prediction of a common fold for several families of glycosyl hydrolases". Proceedings of the National Academy of Sciences of the United States of America. 92 (15): 7090–4. Bibcode:1995PNAS...92.7090H. doi:10.1073/pnas.92.15.7090. PMC 41477. PMID 7624375.
  2. ^ Davies G, Henrissat B (September 1995). "Structures and mechanisms of glycosyl hydrolases". Structure. 3 (9): 853–9. doi:10.1016/S0969-2126(01)00220-9. PMID 8535779.
  3. ^ Henrissat B, Bairoch A (June 1996). "Updating the sequence-based classification of glycosyl hydrolases". The Biochemical Journal. 316 ( Pt 2) (Pt 2): 695–6. doi:10.1042/bj3160695. PMC 1217404. PMID 8687420.
  4. ^ "Home". CAZy.org. Retrieved 2018-03-06.
  5. ^ Lombard V, Golaconda Ramulu H, Drula E, Coutinho PM, Henrissat B (January 2014). "The carbohydrate-active enzymes database (CAZy) in 2013". Nucleic Acids Research. 42 (Database issue): D490-5. doi:10.1093/nar/gkt1178. PMC 3965031. PMID 24270786.
  6. ^ "Glycoside Hydrolase Family 19". CAZypedia.org. Retrieved 2018-03-06.
  7. ^ CAZypedia Consortium (December 2018). "Ten years of CAZypedia: a living encyclopedia of carbohydrate-active enzymes" (PDF). Glycobiology. 28 (1): 3–8. doi:10.1093/glycob/cwx089. PMID 29040563.
  8. ^ Flach J, Pilet PE, Jollès P (August 1992). "What's new in chitinase research?". Experientia. 48 (8): 701–16. doi:10.1007/BF02124285. PMID 1516675. S2CID 37362071.
  9. ^ Henrissat B (December 1991). "A classification of glycosyl hydrolases based on amino acid sequence similarities". The Biochemical Journal. 280 ( Pt 2) (2): 309–16. doi:10.1042/bj2800309. PMC 1130547. PMID 1747104.
  10. ^ Eijsink V, Hoell I, Vaaje-Kolstada G (2010-01-01). "Structure and function of enzymes acting on chitin and chitosan". Biotechnology & Genetic Engineering Reviews. 27 (1): 331–66. doi:10.1080/02648725.2010.10648156. PMID 21415904.
  11. ^ Udaya Prakash NA, Jayanthi M, Sabarinathan R, Kangueane P, Mathew L, Sekar K (May 2010). "Evolution, homology conservation, and identification of unique sequence signatures in GH19 family chitinases". Journal of Molecular Evolution. 70 (5): 466–78. Bibcode:2010JMolE..70..466U. doi:10.1007/s00239-010-9345-z. PMID 20480157. S2CID 2202745.
This article incorporates text from the public domain Pfam and InterPro: IPR000726