retroviral ribonuclease H;
retroviral reverse transcriptase RNaseH;
HIV RNase H
Acting on ester bonds;
Endoribonucleases producing 5'-phosphomonoesters
Endohydrolysis of RNA in RNA/DNA hybrids. Three different cleavage modes 1. sequence-specific internal cleavage of RNA [1-4]. Human immunodeficiency virus type 1 and Moloney murine leukemia virus enzymes prefer to cleave the RNA strand one nucleotide away from the RNA-DNA junction  2. RNA 5'-end directed cleavage 13-19 nucleotides from the RNA end [6,7] 3. DNA 3'-end directed cleavage 15-20 nucleotides away from the primer terminus [8-10].
Comments: Retroviral reverse transcriptase is a multifunctional enzyme responsible for viral replication. To perform this task the enzyme combines two distinct activities. The polymerase domain (EC 22.214.171.124, RNA-directed DNA polymerase) occupies the N-terminal two-thirds of the reverse transcriptase whereas the ribonuclease H domain comprises the C-terminal remaining one-third [13,14]. The RNase H domain of Moloney murine leukemia virus and Human immunodeficiency virus display two metal binding sites [15-17]