Related Experiment Videos
A Prevotella ruminicola B(1)4 operon encoding extracellular polysaccharide hydrolases
R G Gardner1, J E Wells, M W Fields
1Section of Biochemistry, Cornell University, Ithaca, NY 14853, USA.
Current Microbiology
|November 1, 1997
Summary
Researchers identified genes for beta-1,4-endoglucanase and mannanase enzymes from Prevotella ruminicola DNA. These enzymes are crucial for breaking down plant material, with specific genes linked to their functions.
Area of Science:
- Microbiology
- Molecular Biology
- Enzymology
Background:
- Prevotella ruminicola is a rumen bacterium involved in plant biomass degradation.
- Enzymes like endoglucanases and mannanases are key to breaking down complex carbohydrates.
Purpose of the Study:
- To identify and characterize genes encoding beta-1,4-endoglucanase and mannanase activities from Prevotella ruminicola.
- To determine the specific open reading frames (ORFs) responsible for these enzymatic functions.
Main Methods:
- Infection of Escherichia coli with lambda DNA containing Prevotella ruminicola DNA.
- Screening for enzymatic activity in phage plaques.
- DNA fragment isolation, sequencing, and analysis of open reading frames (ORFs).
- Gene cloning and expression in E. coli to confirm enzyme function.
Main Results:
- A 17-kb DNA fragment from Prevotella ruminicola was identified, containing six ORFs.
- ORFs 4 and 5 encoded related beta-1,4-endoglucanases.
- ORF6 encoded a mannanase enzyme, showing homology to Pseudomonas fluorescens mannanase A.
- E. coli expressing ORF6 hydrolyzed mannan, while expression of ORF5 and ORF6 together showed both beta-1,4-endoglucanase and mannanase activity.
- ORF3 showed homology to a cellulose-binding protein.
Conclusions:
- The study successfully identified and characterized the Prevotella ruminicola mannanase gene (ORF6) and two beta-1,4-endoglucanase genes (ORFs 4 and 5).
- These findings provide insights into the genetic basis of carbohydrate degradation by P. ruminicola.