Family 19 chitinase from rice (Oryza sativa L.): substrate-binding subsites demonstrated by kinetic and molecular modeling studies

Family 19 chitinase from rice (Oryza sativa L.): substrate-binding subsites demonstrated by... A family 19 chitinase (OsChia1c, class I) from rice, Oryza sativa L., and its chitin-binding domain-truncated mutant (OsChia1cΔCBD, class II) were produced by the Pichia expression system, and the hydrolytic mechanism toward N-acetylglucosamine hexasaccharide [(GlcNAc)6] was investigated by HPLC analysis of the reaction products. The profile of the time-course of (GlcNAc)6 degradation obtained by OsChia1c was identical to that obtained by OsChia1cΔCBD, indicating that the chitin-binding domain does not significantly participate in oligosaccharide hydrolysis. From the theoretical analysis of the reaction time-course of OsChia1cΔCBD, the free energy changes of sugar residue binding were estimated to be −0.4, −4.7, +3.4, −0.5, −2.3, and −1.0 kcal/mol for the individual subsites of (−3), (−2), (−1), (+1), (+2), and (+3), respectively. The hexasaccharide substrate appears to bind to the enzyme through interactions at the high-affinity sites, (−2) and (+2), and the sugar residues at both ends more loosely bind to the corresponding subsites, (−3) and (+3). The docking study of (GlcNAc)6 with the modeled structure of OsChia1cΔCBD supported the subsite structure estimated from the experimental time-course of hexasaccharide degradation. Since the class II chitinase from barley seeds was reported to possess a similar subsite structure from (−3) to (+3) and a similar free energy distribution, substrate-binding mode of plant chitinases of this class would be similar to each other. Plant Molecular Biology Springer Journals

Family 19 chitinase from rice (Oryza sativa L.): substrate-binding subsites demonstrated by kinetic and molecular modeling studies

Loading next page...
Kluwer Academic Publishers
Copyright © 2003 by Kluwer Academic Publishers
Life Sciences; Biochemistry, general; Plant Sciences; Plant Pathology
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial