CATH Domain 3ithA05

CATH Classification

Level	CATH Code	Description
	3	Alpha Beta
	3.30	2-Layer Sandwich
	3.30.420	Nucleotidyltransferase; domain 5
	3.30.420.10	Ribonuclease H-like superfamily/Ribonuclease H

Domain Context

CATH Clusters

Superfamily	Ribonuclease H-like superfamily/Ribonuclease H
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)

POL_HV1B1

Human immunodeficiency virus type 1 BH10

Gag-Pol polyprotein

PDB Structure

PDB	3ITH
External Links	PDBSum Proteopedia
Method	X-RAY DIFFRACTION
Organism
Primary Citation	Crystal Structure of HIV-1 Reverse Transcriptase Bound to a Non-Nucleoside Inhibitor with a Novel Mechanism of Action Freisz, S., Bec, G., Radi, M., Wolff, P., Crespan, E., Angeli, L., Dumas, P., Maga, G., Botta, M., Ennifar, E. Angew.Chem.Int.Ed.Engl.