CATH Classification

Domain Context

CATH Clusters

Superfamily Acid Proteases
Functional Family Gag-Pol polyprotein

Enzyme Information

3.1.26.13
Retroviral ribonuclease H.
based on mapping to UniProt P03366
Endohydrolysis of RNA in RNA/DNA hybrids. Three different cleavage modes: 1. sequence-specific internal cleavage of RNA. 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. 3. DNA 3'-end directed cleavage 15-20 nucleotides away from the primer terminus.
-!- 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 2.7.7.49) occupies the N-terminal two- thirds of the reverse transcriptase whereas the ribonuclease H domain comprises the C-terminal remaining one-third. -!- The RNase H domain of Moloney murine leukemia virus and Human immunodeficiency virus display two metal binding sites.
2.7.7.7
DNA-directed DNA polymerase.
based on mapping to UniProt P03366
Deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1).
-!- Catalyzes DNA-template-directed extension of the 3'-end of a DNA strand by one nucleotide at a time. -!- Cannot initiate a chain de novo. -!- Requires a primer which may be DNA or RNA. -!- See also EC 2.7.7.49.
2.7.7.-
Nucleotidyltransferases.
based on mapping to UniProt P03366
2.7.7.49
RNA-directed DNA polymerase.
based on mapping to UniProt P03366
Deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1).
-!- Catalyzes RNA-template-directed extension of the 3'-end of a DNA strand by one deoxynucleotide at a time. -!- Cannot initiate a chain de novo. -!- Requires a RNA or DNA primer. -!- DNA can also serve as template. -!- See also EC 2.7.7.7.
3.1.-.-
Acting on ester bonds.
based on mapping to UniProt P03366
3.1.13.2
Exoribonuclease H.
based on mapping to UniProt P03366
3'-end directed exonucleolytic cleavage of viral RNA-DNA hybrid.
-!- This is a secondary reaction to the RNA 5'-end directed cleavage 13-19 nucleotides from the RNA end performed by EC 3.1.26.13.
3.4.23.16
HIV-1 retropepsin.
based on mapping to UniProt P03366
Specific for a P1 residue that is hydrophobic, and P1' variable, but often Pro.
-!- Present in human immunodeficiency virus type 1. -!- Contributes to the maturation of the viral particle, and is a target of antiviral drugs. -!- Active enzyme is a dimer of identical 11-kDa subunits. -!- Similar enzymes occur in other retroviruses. -!- Belongs to peptidase family A2.

UniProtKB Entries (1)

P03366
POL_HV1B1
Human immunodeficiency virus type 1 BH10
Gag-Pol polyprotein

PDB Structure

PDB 1MES
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Molecular basis of HIV-1 protease drug resistance: structural analysis of mutant proteases complexed with cyclic urea inhibitors.
Ala, P.J., Huston, E.E., Klabe, R.M., McCabe, D.D., Duke, J.L., Rizzo, C.J., Korant, B.D., DeLoskey, R.J., Lam, P.Y., Hodge, C.N., Chang, C.H.
Biochemistry