Pathways & interactions
EcoEI R protein C-terminal domain (IPR013670)
Short name: EcoEI_R_C_dom
Overlapping homologous superfamilies
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:220.127.116.11) 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:18.104.22.168) activities.
- Type II enzymes (EC:22.214.171.124) cleave within or at short specific distances from recognition site; most require magnesium; single function (restriction) enzymes independent of methylase.
- Type III enzymes (EC:126.96.36.199) 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:188.8.131.52).
- 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].
- PF08463 (EcoEI_R_C)