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CATH Superfamily 3.40.50.300

P-loop containing nucleotide triphosphate hydrolases

The name of this superfamily has been modified since the most recent official CATH+ release (v4_2_0). At the point of the last release, this superfamily was named:

"
P-loop containing nucleotide triphosphate hydrolases
".

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 475372: Genome polyprotein

There are 3 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
Nuclear-inclusion-a endopeptidase. [EC: 3.4.22.44]
Hydrolyzes glutaminyl bonds, and activity is further restricted by preferences for the amino acids in P6 - P1' that vary with the species of potyvirus, e.g. Glu-Xaa-Xaa-Tyr-Xaa-Gln-|-(Ser or Gly) for the enzyme from tobacco etch virus. The natural substrate is the viral polyprotein, but other proteins and oligopeptides containing the appropriate consensus sequence are also cleaved.
  • The potyviruses cause diseases in plants, and inclusion bodies appear in the host cell nuclei, protein a of these being the endopeptidase.
  • The enzyme finds practical use when encoded in vectors for the artificial expression of recombinant fusion proteins, since it can confer on them the capacity for autolytic cleavage.
  • It is also reported that transgenic plants expressing the enzyme are resistant to viral infection.
  • Belongs to peptidase family C4.
 1 A4KZ49
RNA-directed RNA polymerase. [EC: 2.7.7.48]
Nucleoside triphosphate + RNA(n) = diphosphate + RNA(n+1).
  • Catalyzes RNA-template-directed extension of the 3'-end of an RNA strand by one nucleotide at a time.
  • Can initiate a chain de novo.
  • See also EC 2.7.7.6.
 1 A4KZ49
Helper-component proteinase. [EC: 3.4.22.45]
Hydrolyzes a Gly-|-Gly bond at its own C-terminus, commonly in the sequence -Tyr-Xaa-Val-Gly-|-Gly, in the processing of the potyviral polyprotein.
  • Known from many potyviruses.
  • The helper component-proteinase of the tobacco etch virus is a multifunctional protein with several known activities.
  • The N-terminal region is required for aphid transmission and efficient genome amplification, the central region is required for long-distance movement in plants, and the C-terminal domain has cysteine endopeptidase activity.
  • Belongs to peptidase family C6.
 1 A4KZ49
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