Summary: Restriction endonuclease
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Restriction endonuclease Provide feedback
Prokaryotic family found in type II restriction enzymes containing the hallmark (D/E)-(D/E)XK active site. Presence of catalytic residues implicates this region in the enzymatic cleavage of DNA [1,2].
Waite-Rees PA, Keating CJ, Moran LS, Slatko BE, Hornstra LJ, Benner JS; , J Bacteriol 1991;173:5207-5219.: Characterization and expression of the Escherichia coli Mrr restriction system. PUBMED:1650347 EPMC:1650347
Bujnicki JM, Rychlewski L; , Gene 2001;267:183-191.: Identification of a PD-(D/E)XK-like domain with a novel configuration of the endonuclease active site in the methyl-directed restriction enzyme Mrr and its homologs. PUBMED:11313145 EPMC:11313145
Internal database links
|Similarity to PfamA using HHSearch:||Hjc DUF2034 Mrr_cat_2|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR007560
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 [PUBMED:15121719, PUBMED: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 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+ [PUBMED:1650347]. 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 [PUBMED:16313623]. 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 [PUBMED:11313145].
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Molecular function||DNA binding (GO:0003677)|
|endonuclease activity (GO:0004519)|
|Biological process||DNA restriction-modification system (GO:0009307)|
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This clan includes a large number of nuclease families related to holliday junction resolvases [1,2].
The clan contains the following 123 members:BamHI BpuSI_N Bse634I BsuBI_PstI_RE Cas_APE2256 Cas_Cas02710 Cas_Cas4 Cas_Csm6 Cas_NE0113 CoiA Dna2 DpnII DRP DUF1016 DUF1052 DUF1064 DUF1626 DUF1703 DUF1780 DUF1853 DUF1887 DUF2034 DUF2130 DUF234 DUF2726 DUF2800 DUF2887 DUF3799 DUF3883 DUF4143 DUF4263 DUF4420 DUF506 DUF524 DUF559 DUF790 DUF91 DUF911 EcoRI EcoRII-C eIF-3_zeta Endonuc-BglII Endonuc-BsobI Endonuc-EcoRV Endonuc-FokI_C Endonuc-HincII Endonuc-MspI Endonuc-PvuII Endonuc_BglI Endonuc_Holl ERCC4 Exo5 Herpes_alk_exo Herpes_UL24 Hjc HSDR_N HSDR_N_2 L_protein_N McrBC Mrr_cat Mrr_cat_2 MutH MvaI_BcnI NaeI NARG2_C NERD NgoMIV_restric NotI PDDEXK_1 PDDEXK_2 PDDEXK_3 PDDEXK_4 PDDEXK_5 Pet127 Phage_endo_I R-HINP1I RAI1 RAP RE_AlwI RE_ApaLI RE_Bpu10I RE_Bsp6I RE_CfrBI RE_Eco47II RE_EcoO109I RE_HaeII RE_HindIII RE_HindVP RE_HpaII RE_LlaJI RE_LlaMI RE_MjaI RE_NgoBV RE_NgoPII RE_SacI RE_ScaI RE_SinI RE_TaqI RE_TdeIII RE_XamI RE_XcyI RecU RestrictionMunI RestrictionSfiI RmuC RNA_pol_Rpb5_N Sen15 SfsA TBPIP_N ThaI Tn7_Tnp_TnsA_N Transposase_31 tRNA_int_endo Tsp45I Uma2 UPF0102 VirArc_Nuclease VRR_NUC Vsr XhoI XisH YaeQ YqaJ
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Curation and family details
|Author:||Waterfield DI, Finn RD|
|Number in seed:||227|
|Number in full:||2560|
|Average length of the domain:||113.70 aa|
|Average identity of full alignment:||20 %|
|Average coverage of the sequence by the domain:||32.61 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||7|
|Download:||download the raw HMM for this family|
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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Mrr_cat domain has been found. There are 1 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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