AC   MF_01485;
DC   Protein; auto
TR   HAMAP; MF_01485; -; 1; level=0
XX
Names: RecB
XX
ID   RECB
DE   RecName: Full=RecBCD enzyme subunit RecB;
DE            EC=3.1.11.5;
DE            EC=5.6.2.4;
DE   AltName: Full=DNA 3'-5' helicase subunit RecB;
DE   AltName: Full=Exonuclease V subunit RecB;
DE            Short=ExoV subunit RecB;
DE   AltName: Full=Helicase/nuclease RecBCD subunit RecB;
GN   Name=recB;
XX
CC   -!- FUNCTION: A helicase/nuclease that prepares dsDNA breaks (DSB) for
CC       recombinational DNA repair. Binds to DSBs and unwinds DNA via a highly
CC       rapid and processive ATP-dependent bidirectional helicase activity.
CC       Unwinds dsDNA until it encounters a Chi (crossover hotspot instigator)
CC       sequence from the 3' direction. Cuts ssDNA a few nucleotides 3' to the
CC       Chi site. The properties and activities of the enzyme are changed at
CC       Chi. The Chi-altered holoenzyme produces a long 3'-ssDNA overhang and
CC       facilitates RecA-binding to the ssDNA for homologous DNA recombination
CC       and repair. Holoenzyme degrades any linearized DNA that is unable to
CC       undergo homologous recombination. In the holoenzyme this subunit
CC       contributes ATPase, 3'-5' helicase, exonuclease activity and loads RecA
CC       onto ssDNA.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Exonucleolytic cleavage (in the presence of ATP) in either
CC         5'- to 3'- or 3'- to 5'-direction to yield 5'-
CC         phosphooligonucleotides.; EC=3.1.11.5;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Couples ATP hydrolysis with the unwinding of duplex DNA by
CC         translocating in the 3'-5' direction.; EC=5.6.2.4;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP + H2O = ADP + H(+) + phosphate; Xref=Rhea:RHEA:13065,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:456216; EC=5.6.2.4;
case <FTGroup:1>
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC       Note=Binds 1 Mg(2+) ion per subunit.;
end case
CC   -!- SUBUNIT: Heterotrimer of RecB, RecC and RecD. All subunits contribute
CC       to DNA-binding. Interacts with RecA.
CC   -!- DOMAIN: The N-terminal DNA-binding domain is a ssDNA-dependent ATPase
CC       and has ATP-dependent 3'-5' helicase function. This domain interacts
CC       with RecC.
CC   -!- DOMAIN: The C-terminal domain has nuclease activity and interacts with
CC       RecD. It interacts with RecA, facilitating its loading onto ssDNA.
CC   -!- MISCELLANEOUS: In the RecBCD complex, RecB has a slow 3'-5' helicase,
CC       an exonuclease activity and loads RecA onto ssDNA, RecD has a fast 5'-
CC       3' helicase activity, while RecC stimulates the ATPase and processivity
CC       of the RecB helicase and contributes to recognition of the Chi site.
CC   -!- SIMILARITY: Belongs to the helicase family. UvrD subfamily.
XX
DR   PROSITE; PS51198; UVRD_HELICASE_ATP_BIND; 1; trigger=yes
DR   PROSITE; PS51217; UVRD_HELICASE_CTER; 1; trigger=yes
DR   Pfam; PF00580; UvrD-helicase; 1; trigger=no
DR   Pfam; PF13361; UvrD_C; 1; trigger=no
DR   NCBIfam; TIGR00609; recB; 1; trigger=no
XX
KW   ATP-binding
KW   DNA damage
KW   DNA repair
KW   DNA-binding
KW   Exonuclease
KW   Helicase
KW   Hydrolase
KW   Isomerase
case <FTGroup:1>
KW   Magnesium
KW   Metal-binding
end case
KW   Nuclease
KW   Nucleotide-binding
XX
case <FTGroup:1>
GO   GO:0000287; F:magnesium ion binding
end case
GO   GO:0043138; F:3'-5' DNA helicase activity
GO   GO:0005524; F:ATP binding
GO   GO:0003677; F:DNA binding
GO   GO:0000724; P:double-strand break repair via homologous recombination
XX
FT   From: RECB_ECOLI (P08394)
FT   REGION          Nter..850
FT                   /note="DNA-binding and helicase activity, interacts with
FT                   RecC"
FT   REGION          900..Cter
FT                   /note="Nuclease activity, interacts with RecD and RecA"
FT   ACT_SITE        1080
FT                   /note="For nuclease activity"
FT   Group: 1; Condition: D
FT   BINDING         956
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT   Group: 1; Condition: H
FT   BINDING         1067
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT   Group: 1; Condition: D
FT   BINDING         1080
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT   Group: 1; Condition: D
XX
Size: 987-1496;
Related: None;
Template: P08394;
Scope:
 Bacteria; Actinomycetota
 Bacteria; Bacteroidota
 Bacteria; Chlamydiota
 Bacteria; Chlorobiota
 Bacteria; Deferribacteres
 Bacteria; Pseudomonadota
 Bacteria; Spirochaetota
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: in PARRH, GORPV, LEPBA, LEPBP, SHEB5
Comments: None
XX
# Revision 1.20 2023/11/10
//