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Chitinase Chit62J4 Essential for Chitin Processing by Human Microbiome Bacterium Clostridium paraputrificum J4
- Source :
- Molecules, Vol 26, Iss 5978, p 5978 (2021), Molecules, Volume 26, Issue 19
- Publication Year :
- 2021
- Publisher :
- MDPI AG, 2021.
-
Abstract
- Commensal bacterium Clostridium paraputrificum J4 produces several extracellular chitinolytic enzymes including a 62 kDa chitinase Chit62J4 active toward 4-nitrophenyl N,N′-diacetyl-β-d-chitobioside (pNGG). We characterized the crude enzyme from bacterial culture fluid, recombinant enzyme rChit62J4, and its catalytic domain rChit62J4cat. This major chitinase, securing nutrition of the bacterium in the human intestinal tract when supplied with chitin, has a pH optimum of 5.5 and processes pNGG with Km = 0.24 mM and kcat = 30.0 s−1. Sequence comparison of the amino acid sequence of Chit62J4, determined during bacterial genome sequencing, characterizes the enzyme as a family 18 glycosyl hydrolase with a four-domain structure. The catalytic domain has the typical TIM barrel structure and the accessory domains—2x Fn3/Big3 and a carbohydrate binding module—that likely supports enzyme activity on chitin fibers. The catalytic domain is highly homologous to a single-domain chitinase of Bacillus cereus NCTU2. However, the catalytic profiles significantly differ between the two enzymes despite almost identical catalytic sites. The shift of pI and pH optimum of the commensal enzyme toward acidic values compared to the soil bacterium is the likely environmental adaptation that provides C. paraputrificum J4 a competitive advantage over other commensal bacteria.
- Subjects :
- glycosyl hydrolase family 18
Bacillus cereus
Pharmaceutical Science
Chitin
exochitinase
Article
Analytical Chemistry
chemistry.chemical_compound
QD241-441
Bacterial Proteins
Catalytic Domain
Drug Discovery
Hydrolase
TIM barrel
Humans
Physical and Theoretical Chemistry
adaptation to the environment
Clostridium
chemistry.chemical_classification
biology
Chemistry
Chitinases
Organic Chemistry
Hydrogen-Ion Concentration
biology.organism_classification
Recombinant Proteins
Enzyme assay
Gastrointestinal Microbiome
human commensal bacterium
Enzyme
Biochemistry
Chemistry (miscellaneous)
chitinase
Chitinase
biology.protein
Molecular Medicine
Clostridium paraputrificum
Subjects
Details
- ISSN :
- 14203049
- Volume :
- 26
- Database :
- OpenAIRE
- Journal :
- Molecules
- Accession number :
- edsair.doi.dedup.....1136c72059d806a7b84c3bd0e238e28f
- Full Text :
- https://doi.org/10.3390/molecules26195978