GcvB RNA
Encyclopedia
The gcvB RNA gene encodes a small non-coding RNA
involved in the regulation of a number of amino acid transport systems as well as amino acid biosynthetic genes. The GcvB gene is found in enteric bacteria such as Escherichia coli
. GcvB regulates genes by acting as an antisense binding partner of the mRNAs for each regulated gene. This binding is dependent on binding to a protein called Hfq protein. Transcription
of the GcvB RNA is activated by the adjacent GcvA gene and repressed by the GcvR gene. A deletion of GcvB RNA from Y. pestis changed colony shape as well as reducing growth. It has been shown by gene deletion that GcvB is a regulator of acid resistance in E. coli. GcvB enhances the ability of the bacterium to survive low pH by upregulating the levels of the alternate sigma factor RpoS. A polymeric form of GcvB has recently been identified.
was then used to identify a filamentous structure for the polymer. However, the authors suggest that these long filaments are unlikely to be physiologically relevant. It was shown that a construct containing only the first 61 nucleotides including the first stem-loop was sufficient for polymerisation. Similar results were recently shown for the DsrA RNA
. The physiological relevance of polymerisation is not known.
Non-coding RNA
A non-coding RNA is a functional RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA , non-messenger RNA and functional RNA . The term small RNA is often used for short bacterial ncRNAs...
involved in the regulation of a number of amino acid transport systems as well as amino acid biosynthetic genes. The GcvB gene is found in enteric bacteria such as Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
. GcvB regulates genes by acting as an antisense binding partner of the mRNAs for each regulated gene. This binding is dependent on binding to a protein called Hfq protein. Transcription
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
of the GcvB RNA is activated by the adjacent GcvA gene and repressed by the GcvR gene. A deletion of GcvB RNA from Y. pestis changed colony shape as well as reducing growth. It has been shown by gene deletion that GcvB is a regulator of acid resistance in E. coli. GcvB enhances the ability of the bacterium to survive low pH by upregulating the levels of the alternate sigma factor RpoS. A polymeric form of GcvB has recently been identified.
Targets of GcvB
GcvB has been shown to regulate a large number of genes in E. coli and Salmonella species. GcvB was shown to bind to Oppa and DppA which transport oligopeptides and dipeptides respectively. It has been shown to also regulate gltL, argT, STM, livK, livJ, brnQ, sstT and cycA which are involved in uptake of a variety of amino acids. GcvB RNA also is involved in regulating a variety of genes involved in amino acid biosynthesis such as ilvC, gdhA, thrL and serA.Polymerisation
There is evidence that E. coli GcvB can form polymers. Native polyacrylamide gel electrophoresis was used to show a higher molecular weight band corresponding to a potential polymer. Transmission electron microscopyTransmission electron microscopy
Transmission electron microscopy is a microscopy technique whereby a beam of electrons is transmitted through an ultra thin specimen, interacting with the specimen as it passes through...
was then used to identify a filamentous structure for the polymer. However, the authors suggest that these long filaments are unlikely to be physiologically relevant. It was shown that a construct containing only the first 61 nucleotides including the first stem-loop was sufficient for polymerisation. Similar results were recently shown for the DsrA RNA
DsrA RNA
DsrA RNA is a non-coding RNA that regulates both transcription, by overcoming transcriptional silencing by the nucleoid-associated H-NS protein, and translation, by promoting efficient translation of the stress sigma factor, RpoS...
. The physiological relevance of polymerisation is not known.
Species distribution
The GcvB RNA is found in a range of bacteria including:- Escherichia coliEscherichia coliEscherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
- Yersinia pestisYersinia pestisYersinia pestis is a Gram-negative rod-shaped bacterium. It is a facultative anaerobe that can infect humans and other animals....
- Haemophilus influenzaeHaemophilus influenzaeHaemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the Pasteurellaceae family, it is generally aerobic, but can grow as a facultative anaerobe. H...
- Vibrio choleraeVibrio choleraeVibrio cholerae is a Gram-negative, comma-shaped bacterium. Some strains of V. cholerae cause the disease cholera. V. cholerae is facultatively anaerobic and has a flagella at one cell pole. V...
- Shigella dysenteriaeShigella dysenteriaeShigella dysenteriae is a species of the rod-shaped bacterial genus Shigella. Shigella can cause shigellosis . Shigellae are Gram-negative, non-spore-forming, facultatively anaerobic, non-motile bacteria.S...
- Salmonella typhimurium
- Klebsiella pneumoniaeKlebsiella pneumoniaeKlebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose fermenting, facultative anaerobic, rod shaped bacterium found in the normal flora of the mouth, skin, and intestines....
- Photorhabdus luminescensPhotorhabdus luminescensPhotorhabdus luminescens is a Gammaproteobacteria, belonging to the family Enterobacteriaceae, and is a lethal pathogen of insects....
- Pasteurella multocidaPasteurella multocidaPasteurella multocida is a Gram-negative, non-motile coccobacillus that is penicillin-sensitive and belongs to the Pasteurellaceae family . It can cause avian cholera in birds and a zoonotic infection in humans, which typically is a result of bites or scratches from domestic pets...