Biochemical functions of integrase-binding domain of lens epithelium-derived growth factor

Abstract

Integrase-binding domain (IBD) is a critical region on the lens epithelium-derived growth factor (LEDGF/p75) protein that specifically interacts with human immunodeficiency virus type 1 integrase (HIV-1 IN). In this study, we expressed and purified the IBD, and utilized in endonucleolytic assay and strand transfer assay to investigate whether IBD improve enzymatic activities of HIV-1 IN. Our results showed that IBD along with HIV-1 IN increased the strand transfer activity but not the endonucleolytic activity. Furthermore, our results showed that IBD induced efficient integration of the donor DNA into the target DNA to create half-site integration and full-site integration using plasmid as target DNA. Therefore, it is suggested that LEDGF-IBD itself might be able to increase viral infectivity by enhancing the strand transfer activities of HIV-1 IN and accelerating integration of viral cDNA into cellular chromosomal DNA.