Insights into RNA/DNA hybrid recognition and processing by RNase H from the crystal structure of a non-specific enzyme-dsDNA complex.

ABSTRACT: Ribonuclease HI (RNase H) is a member of the nucleotidyl-transferase superfamily and endo-nucleolytically cleaves the RNA portion in RNA/DNA hybrids and removes RNA primers from Okazaki fragments. The enzyme also binds RNA and DNA duplexes but is unable to cleave either. Three-dimensional structures of bacterial and human RNase H catalytic domains bound to RNA/DNA hybrids have revealed the basis for substrate recognition and the mechanism of cleavage. In order to visualize the enzyme's interactions with duplex DNA and to establish the structural differences that afford tighter binding to RNA/DNA hybrids relative to dsDNA, we have determined the crystal structure of Bacillus halodurans RNase H in complex with the B-form DNA duplex [d(CGCGAATTCGCG)](2). The structure demonstrates that the in

SUBMITTER: Pallan PS 

PROVIDER: S-EPMC3689302 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature