Poster abstracts
Poster number 84 submitted by Le Luo
Secondary Structure Probing of 7SK upon HEXIM1 Binding
Le Luo (Department of Chemistry, Case Western Reserve University), Blanton S. Tolbert (Department of Chemistry, Case Western Reserve University)
Abstract:
During transactivation of the HIV-1 proviral genome, P-TEFb is recruited to the nascent RNAP II complex. P-TEFb exists in equilibrium between an inactive and active pool, where the 7SK snRNA along with the cellular protein HEXIM1 sequesters P-TEFb in its inactive state. Previous EMSA studies have demonstrated the specific binding between HEXIM1 and 7SK, however, the mechanism of the HEXIM1-7SK interaction is not clear. A structural profile of 7SK-HEXIM1 complex will demonstrate the specific binding site and binding mechanism, thus, elucidate the molecular mechanism of P-TEFb regulation. In this study, mutagenesis of the 7SK stem loops demonstrated that more than one structural element of this 7SK snRNA are involved in the HEXIM1-7SK binding event; the DMS modification and sequencing profiles will provide the secondary structure of 7SK and the structural changes when binding with HEXIM1.
Keywords: 7SK, HEXIM1, DMS