In molecular biology, VR-RNA is a small RNA produced by Clostridium perfringens. It functions as a regulator of the two-component VirR/VirS system.^[1][2]

VR-RNA regulates numerous genes including:

• Toxin-encoding genes plc, colA and cpb2^[3][4][5]
• Other virulence-related genes such as hyaluronidases and sialidase^[6]
• Possible collagen adhesin gene (cna)^[7]
• Extracellular nuclease, cadA^[8]
• Enzymes such as Acid phosphatase, Heme oxygenase HemO and N-acetylglucosaminidases^[9][10][11]
• Genes encoding transport proteins^[12]
• Genes involved in carbohydrate metabolism^[13]
• Genes encoding transport proteins^[14]
• Arginine deiminase (ADI) pathway genes^[15]
• Genes involved in citrate metabolism^[16]

VR-RNA regulates the toxin colA (collagenase) by base-pairing to colA mRNA, the 3′ end of VR-RNA base-pairs to a region in the 5′UTR of the colA mRNA. This induces cleavage of the colA mRNA in the 5′ UTR and leads to stabilisation of the mRNA and increased translation.^[17]

• Bacterial small RNA