Related Experiment Video
Updated: Jul 8, 2026
07:28
Live Cell Fluorescence Microscopy to Observe Essential Processes During Microbial Cell Growth
Published on: November 24, 2017
Glucomannan utilization operon of Bacillus subtilis
Yoshito Sadaie1, Hisashi Nakadate, Reiko Fukui
1Department of Molecular Biology, Faculty of Science, Saitama University, Saitama City, Japan. ysadaie@molbiol.saitama-u.ac.jp
FEMS Microbiology Letters
|January 8, 2008
Summary
Bacillus subtilis utilizes glucomannan via the gmu operon, activated by its breakdown products. An internal repressor (gmuR) controls this operon
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Bacillus subtilis possesses a glucomannan utilization operon (gmuBACDREFG).
- Understanding the regulation of this operon is crucial for microbial biotechnology.
Purpose of the Study:
- To characterize the glucomannan utilization operon (gmuBACDREFG) in Bacillus subtilis.
- To identify the regulatory mechanisms governing its transcription.
Main Methods:
- Gene disruption to study operon regulation.
- Analysis of transcriptional induction by glucomannan and its degradation products.
Main Results:
- Operon transcription is induced by konjac glucomannan and requires the gmuG mannanase gene.
- Cellobiose and mannobiose act as potent transcriptional inducers.
- The gmuR gene encodes a repressor, with its disruption enhancing operon transcription.
Conclusions:
- Glucomannan utilization in B. subtilis is regulated by the gmu operon.
- Transcriptional expression is induced by glucomannan degradation products.
- An internal repressor (gmuR) negatively controls operon expression.
Related Concept Videos
02:09Operons
Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor...
02:09Operons
Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor...
01:25Inducible Operons: lac Operon
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside...
01:58Prokaryotic Transcriptional Activators and Repressors
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
01:28Global Regulatory Systems
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
01:23Operon Model
The operon model represents a fundamental mechanism of gene regulation in prokaryotes, enabling coordinated expression of genes involved in related metabolic or functional pathways. Operons consist of structural genes, a promoter, and an operator, with transcription regulated by repressors, activators, and small effector molecules.Structure and Function of OperonsAn operon is a cluster of structural genes transcribed together under the control of a single promoter. The promoter region...