YkoK leader
Encyclopedia
The Ykok leader or M-box is a Mg2+-sensing RNA structure
that controls the expression
of Magnesium ion transport proteins in bacteria. It is a distinct structure to the Magnesium responsive RNA element.
The Ykok leader was originally described as a conserved
sequence with potential riboswitch
function found upstream of the B. subtilis ykoK gene and genes with related functions in other bacteria. Examples of the conserved M-box RNA structure occur upstream of each of the three major families of Mg2+ transporters in various bacterial species. The molecular structure of the M-box example upstream of the B. subtilis ykoK gene includes six bound Mg2+ ions. Biochemical studies indicate that this M-Box RNA compacts in the presence of Mg2+ and other divalent
ions. This folding process appears to disrupt an antiterminator structure, and thereby allow a transcription terminator structure to form. As expected from this model, B. subtilis cells repress expression of a downstream reporter gene when grown in the presence of Mg2+. Therefore, the M-box appears to function as a genetic "off" switch that is important for maintaining Mg2+ homeostasis
in bacteria.
Cis-regulatory element
A cis-regulatory element or cis-element is a region of DNA or RNA that regulates the expression of genes located on that same molecule of DNA . This term is constructed from the Latin word cis, which means "on the same side as". These cis-regulatory elements are often binding sites for one or...
that controls the expression
Gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
of Magnesium ion transport proteins in bacteria. It is a distinct structure to the Magnesium responsive RNA element.
The Ykok leader was originally described as a conserved
Conserved sequence
In biology, conserved sequences are similar or identical sequences that occur within nucleic acid sequences , protein sequences, protein structures or polymeric carbohydrates across species or within different molecules produced by the same organism...
sequence with potential riboswitch
Riboswitch
In molecular biology, a riboswitch is a part of an mRNA molecule that can directly bind a small target molecule, and whose binding of the target affects the gene's activity. Thus, an mRNA that contains a riboswitch is directly involved in regulating its own activity, in response to the...
function found upstream of the B. subtilis ykoK gene and genes with related functions in other bacteria. Examples of the conserved M-box RNA structure occur upstream of each of the three major families of Mg2+ transporters in various bacterial species. The molecular structure of the M-box example upstream of the B. subtilis ykoK gene includes six bound Mg2+ ions. Biochemical studies indicate that this M-Box RNA compacts in the presence of Mg2+ and other divalent
Divalent
In chemistry, a divalent ion or molecule has a valence of two and thus can form two bonds with other ions or molecules. An older term for divalent is bivalent....
ions. This folding process appears to disrupt an antiterminator structure, and thereby allow a transcription terminator structure to form. As expected from this model, B. subtilis cells repress expression of a downstream reporter gene when grown in the presence of Mg2+. Therefore, the M-box appears to function as a genetic "off" switch that is important for maintaining Mg2+ homeostasis
Homeostasis
Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
in bacteria.