P27 cis-regulatory element

The p27 cis-regulatory element is a structured G/C rich RNA element located in the 5' UTR of p27 mRNA. This element contributes to cell cycle regulated translation and when deleted leads to a 50% drop in regulation. The element is thought to be able to form several different structures with similar free energy. It has been suggested that proteins may only bind to a specific structure thus conformational changes could regulate translation.