SprD

In molecular biology SprD is a non-coding RNA expressed on pathogenicity islands in Staphylococcus aureus. It was identified in silico along with a number of other sRNAs through microarray analysis which were confirmed using a Northern blot. SprD has been found to significantly contribute to causing disease in an animal model.

Function

SprD is located between genes scn and chp in the immune system|innate immune evasion] cluster of the S. aureus genome. Its placement within this region was the first indication of a virulence-factor regulatory function.
SprD binds with sbi mRNA which encodes an immune evasion protein. It occludes the Shine-Dalgarno sequence and the initiation codon of sbi, forming a sbi mRNA-SprD duplex repressing the translation of the mRNA.
sbi protein interferes with the host's innate immune response by binding Factor H, Complement component 3 and IgG.