Various organisms have at least one enzyme that degrades the RNA of RNA-DNA hybrids. These ribonucleases H (RNases H), so far, fall into two classes based upon primary amino acid sequence similarity. From our studies, we know that the well- characterized Escherichia coli RNase HI has homologs in many different species including human and mouse. We know that these mammalian proteins resemble in sequence and function the RNase H1 of Saccharomyces cerevisiae by having a double- stranded RNA-binding activity in addition to the RNase H activity. Synthesis of mRNA for RNase H1 of S. cerevisiae is constant throughout the cell cycle whereas the mRNA for RNase H2 is most abundant at S and G2/M phase. Double-deletion mutant strains are viable yet there are diffferences in sensitivities of the single mutant strains to caffeine and hydroxyurea. The level of mRNA and RNase H2(35) protein increase in the absence of RNase H1. These results suggest that RNase H1 is involved in housekeeping function, removing inadvertently formed RNA-DNA hybrids while RNase H2 is involved in DNA replication and repair. - Ribonuclease H, cell cycle, DNA replication, DNA repair

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Intramural Research (Z01)
Project #
1Z01HD000068-28
Application #
6290149
Study Section
Special Emphasis Panel (LMG)
Project Start
Project End
Budget Start
Budget End
Support Year
28
Fiscal Year
1999
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Nowotny, Marcin; Gaidamakov, Sergei A; Ghirlando, Rodolfo et al. (2007) Structure of human RNase H1 complexed with an RNA/DNA hybrid: insight into HIV reverse transcription. Mol Cell 28:264-76
Budihas, Scott R; Gorshkova, Inna; Gaidamakov, Sergei et al. (2005) Selective inhibition of HIV-1 reverse transcriptase-associated ribonuclease H activity by hydroxylated tropolones. Nucleic Acids Res 33:1249-56
Gaidamakov, Sergei A; Gorshkova, Inna I; Schuck, Peter et al. (2005) Eukaryotic RNases H1 act processively by interactions through the duplex RNA-binding domain. Nucleic Acids Res 33:2166-75
Nowotny, Marcin; Gaidamakov, Sergei A; Crouch, Robert J et al. (2005) Crystal structures of RNase H bound to an RNA/DNA hybrid: substrate specificity and metal-dependent catalysis. Cell 121:1005-16
Chan, King C; Budihas, Scott R; Le Grice, Stuart F J et al. (2004) A capillary electrophoretic assay for ribonuclease H activity. Anal Biochem 331:296-302
Jeong, Ho-Sang; Backlund, Peter S; Chen, Hao-Chia et al. (2004) RNase H2 of Saccharomyces cerevisiae is a complex of three proteins. Nucleic Acids Res 32:407-14
Broccoli, Sonia; Rallu, Fabien; Sanscartier, Patrick et al. (2004) Effects of RNA polymerase modifications on transcription-induced negative supercoiling and associated R-loop formation. Mol Microbiol 52:1769-79
Backer, Marina V; Gaynutdinov, Timur I; Gorshkova, Inna I et al. (2003) Humanized docking system for assembly of targeting drug delivery complexes. J Control Release 89:499-511
Pileur, Frederic; Andreola, Marie-Line; Dausse, Eric et al. (2003) Selective inhibitory DNA aptamers of the human RNase H1. Nucleic Acids Res 31:5776-88
Cerritelli, Susana M; Frolova, Ella G; Feng, Chiguang et al. (2003) Failure to produce mitochondrial DNA results in embryonic lethality in Rnaseh1 null mice. Mol Cell 11:807-15

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