EcoEI R protein C-terminal domain (IPR013670)

Short name: EcoEI_R_C_dom

Overlapping homologous superfamilies


Domain relationships



There are four classes of restriction endonucleases: types I, II,III and IV. All types of enzymes recognise specific short DNA sequences and carry out the endonucleolytic cleavage of DNA to give specific double-stranded fragments with terminal 5'-phosphates. They differ in their recognition sequence, subunit composition, cleavage position, and cofactor requirements [PMID: 15121719, PMID: 12665693], as summarised below:

  • Type I enzymes (EC: cleave at sites remote from recognition site; require both ATP and S-adenosyl-L-methionine to function; multifunctional protein with both restriction and methylase (EC: activities.
  • Type II enzymes (EC: cleave within or at short specific distances from recognition site; most require magnesium; single function (restriction) enzymes independent of methylase.
  • Type III enzymes (EC: cleave at sites a short distance from recognition site; require ATP (but doesn't hydrolyse it); S-adenosyl-L-methionine stimulates reaction but is not required; exists as part of a complex with a modification methylase methylase (EC:
  • Type IV enzymes target methylated DNA.

This entry represents the C-terminal domain found in both the R subunit of type I enzymes and the Res subunit of type III enzymes. The type I enzymes include EcoEI, which recognises 5'-GAGN(7)ATGC-3; the R protein (HsdR) is required for both nuclease and ATPase activity [PMID: 8412658, PMID: 10449767].

GO terms

Biological Process

GO:0006304 DNA modification

Molecular Function

GO:0003677 DNA binding
GO:0003824 catalytic activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.