LIS - Legume Information System
Information about legume traits for crop improvement
CicerMine
v5.1.0.3
Cicer data from the Legume Information System
v5.1.0.3
Cicer data from the Legume Information System
| Type | Domain |
| Description | 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 [ , ], as summarised below:Type I enzymes ( ) cleave at sites remote from recognition site; require both ATP and S-adenosyl-L-methionine to function; multifunctional protein with both restriction and methylase ( ) activities. Type II enzymes ( ) cleave within or at short specific distances from recognition site; most require magnesium; single function (restriction) enzymes independent of methylase. Type III enzymes ( ) 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 ( ). Type IV enzymes target methylated DNA.This entry represents Mrr, a type IV restriction endonuclease involved in the acceptance of modified foreign DNA, restricting both adenine- and cytosine-methylated DNA. Plasmids carrying HincII, HpaI, and TaqI R and M genes are severely restricted in Escherichia coli strains that are Mrr+ []. Mrr appears to be the final effector of the bacterial SOS response, which is not only a vital reply to DNA damage but also constitutes an essential mechanism for the generation of genetic variability that in turn fuels adaptation and resistance development in bacterial populations []. Mrr possesses a cleavage domain that is similar to that found in type II restriction enzymes, however it has an unusual glutamine residue at the central position of the (D/E)-(D/E)XK hallmark of the active site []. |
| Short Name | Restrct_endonuc_IV_Mrr |
