Flavivirus 3' UTR cis-acting replication element (CRE)

The Flavivirus 3' UTR cis-acting replication element (CRE) is an RNA element that is thought to play a crucial role in replication and is thought to be needed for the formation of a "replication complex". Although evidence has been presented for an existence of a pseudoknot structure in this RNA, it does not appear to be well conserved across flaviviruses. Deletions of the 3' UTR of flaviviruses have been shown to be lethal for infectious clones.