The Sxy 5′ UTR element is an
RNA element that controls expression of the sxy gene in ''
H. influenzae''. The sxy gene is a transcription factor (also known as TfoX) that regulates
competence
Broad concept article:
*Competence (polyseme), capacity or ability to perform effectively
Competence or competency may also refer to:
*Competence (human resources), ability of a person to do a job properly
**Competence-based management, performa ...
which is the ability of bacteria to take up DNA from their environment.
When the sxy gene is deleted the bacterium loses the ability to express genes in the competence regulon. Cameron ''et al.'' recently showed that mutations in the 5′ end of the sxy gene lead to hypercompetance.
They showed that this region formed an RNA secondary structure that occludes the
Shine-Dalgarno sequence. Mutations that interfere with the stability of this secondary structure lead to increased translation of sxy followed by upregulation of the competence regulon.
tfoR RNA
In the fellow
gammaproteobacterium
''Gammaproteobacteria'' is a class of bacteria in the phylum ''Pseudomonadota'' (synonym ''Proteobacteria''). It contains about 250 genera, which makes it the most genus-rich taxon of the Prokaryotes. Several medically, ecologically, and scienti ...
''
Vibrio cholerae
''Vibrio cholerae'' is a species of Gram-negative bacteria, Gram-negative, Facultative anaerobic organism, facultative anaerobe and Vibrio, comma-shaped bacteria. The bacteria naturally live in Brackish water, brackish or saltwater where they att ...
'', a different RNA regulatory system is used.
Here, a sRNA named 'tfoR' positively regulates expression of the sxy (tfoX) protein.
The RNA element responds to
chitin
Chitin (carbon, C8hydrogen, H13oxygen, O5nitrogen, N)n ( ) is a long-chain polymer of N-Acetylglucosamine, ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is the second most abundant polysaccharide in nature (behind only cell ...
, which is an important regulator of competence in ''V. cholera''.
Deletion of tfoR removed all competence for exogenous DNA in ''V. cholera'' ''
in vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, an ...
''.
secondary structure
Protein secondary structure is the local spatial conformation of the polypeptide backbone excluding the side chains. The two most common Protein structure#Secondary structure, secondary structural elements are alpha helix, alpha helices and beta ...
of tfoR sRNA.
References
External links
Rfam entry for sxy 5′ UTR element
{{DEFAULTSORT:Sxy 5' UTR element
Cis-regulatory RNA elements