In molecular biology, the FasX small RNA (fibronectin/fibrinogen-binding/haemolytic-activity/streptokinase-regulator-X) is a non-coding

small RNA Small RNA (sRNA) are polymeric RNA molecules that are less than 200 nucleotides in length, and are usually non-coding Non-coding DNA (ncDNA) sequences are components of an organism's DNA that do not encode protein sequences. Some non-coding DNA ...

(sRNA) produced by all group A '' Streptococcus''. FasX has also been found in species of group D and group G '' Streptococcus''. FasX regulates expression of secreted virulence factor streptokinase (SKA), encoded by the ''ska'' gene. FasX

base pairs A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

to the 5' end of the ska mRNA, increasing the stability of the mRNA, resulting in elevated levels of streptokinase expression. FasX negatively regulates the expression of

pili Pili may refer to: Common names of plants * ''Canarium ovatum'', a Philippine tree that is a source of the pili nut * ''Heteropogon contortus'', a Hawaiian grass used to thatch structures Places * Pili, Camarines Sur, is a municipality in the ...

and fibronectin-binding proteins on the bacterial cell surface. It binds to the 5' untranslated region of genes in the FCT-region in a serotype-specific manner, reducing the stability of and inhibiting translation of the pilus

biosynthesis Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...

operon mRNA by occluding the ribosome-binding site through a simple Watson-Crick base-pairing mechanism.

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