AC   MF_01487;
DC   Protein; auto
TR   HAMAP; MF_01487; -; 1; level=0
XX
Names: RecD
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ID   RECD
DE   RecName: Full=RecBCD enzyme subunit RecD;
DE            EC=5.6.2.3;
DE   AltName: Full=DNA 5'-3' helicase subunit RecD;
DE   AltName: Full=Exonuclease V subunit RecD;
DE            Short=ExoV subunit RecD;
DE   AltName: Full=Helicase/nuclease RecBCD subunit RecD;
GN   Name=recD;
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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 has
CC       ssDNA-dependent ATPase and 5'-3' helicase activity. When added to pre-
CC       assembled RecBC greatly stimulates nuclease activity and augments
CC       holoenzyme processivity. Negatively regulates the RecA-loading ability
CC       of RecBCD.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Couples ATP hydrolysis with the unwinding of duplex DNA at the
CC         replication fork by translocating in the 5'-3' direction. This
CC         creates two antiparallel DNA single strands (ssDNA). The leading
CC         ssDNA polymer is the template for DNA polymerase III holoenzyme which
CC         synthesizes a continuous strand.; EC=5.6.2.3;
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=5.6.2.3;
CC   -!- SUBUNIT: Heterotrimer of RecB, RecC and RecD. All subunits contribute
CC       to DNA-binding.
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 RecD family.
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DR   Pfam; PF21185; RecD_N; 0-1; trigger=no
DR   Pfam; PF13538; UvrD_C_2; 1; trigger=no
DR   NCBIfam; TIGR01447; recD; 1; trigger=no
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case <FT:1>
KW   ATP-binding
KW   Nucleotide-binding
end case
KW   DNA damage
KW   DNA repair
KW   DNA-binding
KW   Exonuclease
KW   Helicase
KW   Hydrolase
KW   Isomerase
KW   Nuclease
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GO   GO:0043139; F:5'-3' DNA helicase activity
case <FT:1>
GO   GO:0005524; F:ATP binding
end case
GO   GO:0003677; F:DNA binding
GO   GO:0000724; P:double-strand break repair via homologous recombination
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FT   From: RECD_ECOLI (P04993)
FT   BINDING         171..178
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT   Condition: G-G-P-G-T-G-K-T
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Size: 554-640;
Related: MF_01488!;
Template: P04993;
Scope:
 Bacteria; Actinomycetota
 Bacteria; Bacteroidota
 Bacteria; Chlamydiota
 Bacteria; Chlorobiota
 Bacteria; Deferribacteres
 Bacteria; Pseudomonadota
 Bacteria; Spirochaetota
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: None
Comments: There is a related helicase (RecD2, MF_01488) that is not found
 associated with RecB and RecC, although some organisms have both genes.
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# Revision 1.20 2023/12/14
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