The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was named:

"
Ribonuclease H-like superfamily/Ribonuclease H
".

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 17: POL polyprotein

There are 5 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Retroviral ribonuclease H. [EC: 3.1.26.13]
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.
34 O12158 O41798 O89290 O89940 O93215 P03366 P03367 P03369 P04585 P04587
(24 more...)
DNA-directed DNA polymerase. [EC: 2.7.7.7]
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.
34 O12158 O41798 O89290 O89940 O93215 P03366 P03367 P03369 P04585 P04587
(24 more...)
Exoribonuclease H. [EC: 3.1.13.2]
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.
34 O12158 O41798 O89290 O89940 O93215 P03366 P03367 P03369 P04585 P04587
(24 more...)
RNA-directed DNA polymerase. [EC: 2.7.7.49]
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.
34 O12158 O41798 O89290 O89940 O93215 P03366 P03367 P03369 P04585 P04587
(24 more...)
HIV-1 retropepsin. [EC: 3.4.23.16]
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.
34 O12158 O41798 O89290 O89940 O93215 P03366 P03367 P03369 P04585 P04587
(24 more...)