Cloning, expression, purification and preliminary crystallographic studies of the adenylate/uridylate-rich element-binding protein HuR complexed with its target RNA.

Adenylate/uridylate-rich elements (AREs), which are found in the 3'-untranslated region (UTR) of many mRNAs, influence the stability of cytoplasmic mRNA. HuR (human antigen R) binds to AREs and regulates various genes. In order to reveal the RNA-recognition mechanism of HuR protein, an RNA-binding region of human HuR containing two N-terminal RNA-recognition motif domains bound to an 11-base RNA fragment has been crystallized. The crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 42.4, b = 44.9, c = 91.1 A. X-ray diffraction data were collected to 1.8 A resolution.