Cloning, purification and structure determination of the HIV integrase‐binding domain of lens epithelium‐derived growth factor.

Lens epithelium‐derived growth factor (LEDGF)/p75 is the dominant binding partner of HIV‐1 integrase in human cells. The crystal structure of the HIV integrase‐binding domain (IBD) of LEDGF has been determined in the absence of ligand. IBD was overexpressed in <italic>Escherichia coli</italic>, purified and crystallized by sitting‐drop vapour diffusion. X‐ray diffraction data were collected at Diamond Light Source to a resolution of 2.05 Å. The crystals belonged to space group <italic>P</italic>21, with eight polypeptide chains in the asymmetric unit arranged as an unusual octamer composed of four domain‐swapped IBD dimers. IBD exists as a mixture of monomers and dimers in concentrated solutions, but the dimers are unlikely to be biologically relevant. [ABSTRACT FROM AUTHOR]