HAMAP

Accession	MF_01453
Dates	4-JUN-2009 (Created) 18-NOV-2010 (Last updated, Version 9)

Data class

Protein

Predictors

HAMAP; MF_01453; [distribution of match scores in UniProtKB];[seed alignment for MF_01453]

Names

AddB_type2

Identifier

ADDB

Protein name

RecName: Full=ATP-dependent helicase/deoxyribonuclease subunit B; EC=3.1.-.-; EC=3.6.4.12; AltName: Full=ATP-dependent helicase/nuclease RexB;

Gene name

rexB

FUNCTION: The heterodimer acts as both an ATP-dependent DNA helicase and an ATP-dependent, dual-direction single-stranded exonuclease. Recognizes the chi site generating a DNA molecule suitable for the initiation of homologous recombination. This subunit has 5' -> 3' nuclease activity (By similarity).

CATALYTIC ACTIVITY: ATP + H(2)O = ADP + phosphate.

COFACTOR: Binds 1 4Fe-4S cluster. Magnesium (Potential).

COFACTOR: Magnesium (By similarity).

SUBUNIT: Heterodimer of AddA and RexB (By similarity).

SIMILARITY: Belongs to the helicase family. AddB/RexB type 2 subfamily.

TIGRFAMs

TIGR02774; rexB_recomb; 1;

ATP-binding, DNA damage, DNA repair, Exonuclease, Hydrolase, Nuclease, Nucleotide-binding.

4Fe-4S, Iron, Iron-sulfur, Metal-binding.

GO:0005524; Molecular function: ATP binding.
GO:0008409; Molecular function: 5'-3' exonuclease activity.
GO:0003690; Molecular function: double-stranded DNA binding.

GO:0051536; Molecular function: iron-sulfur cluster binding.

GO:0000724; Biological process: double-strand break repair via homologous recombination.

From: ADDB_LACLM (A2RH76)
Key		From		To		Description		Condition		FTGroup
METAL (Optional)		766		766		Iron-sulfur (4Fe-4S) (Potential)		C		1
METAL (Optional)		1056		1056		Iron-sulfur (4Fe-4S) (Potential)		C		1
METAL (Optional)		1059		1059		Iron-sulfur (4Fe-4S) (Potential)		C		1
METAL (Optional)		1065		1065		Iron-sulfur (4Fe-4S) (Potential)		C		1

Size range:	1071-1260 amino acids
Related UniRules:	MF_01452 (ADDB)
Template:	A2RH76 (ADDB_LACLM); Q97QQ0 (ADDB_STRPN): [Recover all]
Scope:	Bacteria; Firmicutes
Fusion:	Nter: None; Cter: None
Duplicate:	None
Plasmid encoded:	None
Comments:	The iron-sulfur center has been shown to exist in the related AddB protein from B.subtilis; its suggested presence in a few members of this family is based solely on sequence conservation. Two related subfamiles of this protein exist; addB in Bacillus and Staphylococcus (MF_01452), and rexB in Lactobacillus and Streptococcus (this family). In most Lactobacillales there is no 4Fe-4S center; this has been suggested (PubMed:19129187) to occur in organisms which inhabit a low- iron environment.