ExPASy Proteomics Server

Accession	MF_00015
Dates	1-JUN-2001 (Created) 25-NOV-2009 (Last updated, Version 32)

Data class

Protein

Predictors

HAMAP; MF_00015; [distribution of match scores in UniProtKB];[seed alignment for MF_00015]

Names

LexA

Identifier

LEXA

Protein name

RecName: Full=LexA repressor; EC=3.4.21.88;

Gene name

lexA

FUNCTION: Represses a number of genes involved in the response to DNA damage (SOS response), including recA and lexA. In the presence of single-stranded DNA, recA interacts with lexA causing an autocatalytic cleavage which disrupts the DNA-binding part of lexA, leading to derepression of the SOS regulon and eventually DNA repair (By similarity).

FUNCTION: Represses a number of genes involved in the response to DNA damage (SOS response), including recA and lexA. Binds to the 16 bp palindromic sequence 5'-CTGTATATATATACAG-3'. In the presence of single-stranded DNA, recA interacts with lexA causing an autocatalytic cleavage which disrupts the DNA-binding part of lexA, leading to derepression of the SOS regulon and eventually DNA repair (By similarity).

CATALYTIC ACTIVITY: Hydrolysis of Ala-|-Gly bond in repressor lexA.

SUBUNIT: Homodimer (By similarity).

SIMILARITY: Belongs to the peptidase S24 family.

Pfam	PF01726; LexA_DNA_bind; 1; PF00717; Peptidase_S24; 1;
PRINTS	PR00726; LEXASERPTASE; 1;
TIGRFAMs	TIGR00498; lexA; 1;

Transcription, Transcription regulation, Repressor, DNA-binding, DNA damage, Autocatalytic cleavage, Hydrolase, DNA replication, DNA repair, SOS response.

GO:0003677; Molecular function: DNA binding.
GO:0004252; Molecular function: serine-type endopeptidase activity.
GO:0006281; Biological process: DNA repair.
GO:0006260; Biological process: DNA replication.
GO:0045892; Biological process: negative regulation of transcription, DNA-dependent.
GO:0006974; Biological process: response to DNA damage stimulus.
GO:0009432; Biological process: SOS response.

From: LEXA_ECOLI (P0A7C2)
Key		From		To		Description		Condition		FTGroup
DNA_BIND		28		48		H-T-H motif (By similarity)
ACT_SITE		119		119		For autocatalytic cleavage activity (By similarity)		S
ACT_SITE		156		156		For autocatalytic cleavage activity (By similarity)		K
SITE		84		85		Cleavage; by autolysis (By similarity)		A-G

Size range:	192-275 amino acids
Related UniRules:	None
Template:	P31080 (LEXA_BACSU); P0A7C2 (LEXA_ECOLI); Q9ZFA4 (LEXA_RHOS4): [Recover all]
Scope:	Bacteria
Fusion:	Nter: None; Cter: None
Duplicate:	in GEOSL, NOCFA, PSEPK, PSESM, XANAC, XANCP
Plasmid encoded:	None