Talk abstracts

Talk on Wednesday 03:00-03:15pm submitted by Brandon Crowe

The solution structure and nucleosome binding of the PWWP domain of LEDGF/p75

Brandon L. Crowe (Department of Biochemistry, The Ohio State Universtiy), Jocelyn Eidahl (Department of Pharmacy, The Ohio State Universtiy), Mamuka Kvaratskhelia (Department of Pharmacy, The Ohio State Universtiy), Mark P. Foster (Department of Biochemistry, The Ohio State University)

Abstract:
Lens epithelium derived growth factor p75 (LEDGF/p75) is a transcription factor that promotes resistance to stress induced cell death. LEDGF is a large multi domain protein containing a PWWP domain, 2 copies of the AT hook DNA binding domain, and a domain at the C-terminus termed the integrase binding domain (IBD). HIV-1 has been shown to hijack LEDGF in order integrate itself into the host genome, as LEDGF knock-out cell lines reduce the ability of HIV-1 to infect cells by more than 95%. LEDGF functions as a bimodal tether for HIV-1 integration. The IBD interacts with the preintegration complex of HIV-1, whereas the PWWP domain and AT hooks bind cellular chromatin. The molecular basis for the integrase-LEDGF interaction is understood, while the mechanism of chromatin binding is currently unknown. Mutational analysis has shown the importance of the PWWP domain for specific binding of LEDGF to chromatin needed for targeting of HIV-1 integration. We have determined the solution structure of the N-terminal PWWP domain by nuclear magnetic resonance (NMR). We also show that the PWWP domain alone has the ability to bind nucleosomes. These data along with mutational analysis allows us to make structural hypotheses for the direct interaction of LEDGF/p75 to chromatin and thus the targeting of HIV-1 integration that occurs in vivo.

Keywords: HIV, LEDGFp75, NMR solution structure