P0A7C2 (LEXA_ECOLI) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
LexA repressor
EC=3.4.21.88

Gene names

Name:	lexA
Synonyms:	exrA, spr, tsl, umuA
Ordered Locus Names:	b4043, JW4003

Organism

Escherichia coli (strain K12)

Taxonomic identifier

83333 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia

Protein attributes

Sequence length	202 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

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. Ref.9 Ref.10
Catalytic activity	Hydrolysis of Ala-|-Gly bond in repressor lexA. HAMAP MF_00015
Subunit structure	Homodimer.
Sequence similarities	Belongs to the peptidase S24 family.

Ontologies

Keywords
Biological process	DNA damage DNA repair DNA replication SOS response Transcription Transcription regulation
Ligand	DNA-binding
Molecular function	Hydrolase Repressor
PTM	Autocatalytic cleavage
Technical term	3D-structure Complete proteome Reference proteome
Gene Ontology (GO)
Biological process	DNA repair Inferred from electronic annotation. Source: UniProtKB-KW DNA replication Inferred from electronic annotation. Source: UniProtKB-KW SOS response Inferred from electronic annotation. Source: UniProtKB-KW proteolysis Inferred from electronic annotation. Source: InterPro regulation of transcription, DNA-dependent Inferred from electronic annotation. Source: UniProtKB-KW transcription, DNA-dependent Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	DNA binding Inferred from direct assay. Source: EcoliWiki serine-type endopeptidase activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
rpsE	P0A7W1	1	EBI-553416,EBI-543949

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 202

202

LexA repressor HAMAP MF_00015

PRO_0000170031

Regions

DNA binding

28 – 48

21

H-T-H motif HAMAP MF_00015

Sites

Active site

119

1

For autocatalytic cleavage activity By similarity

Active site

156

1

For autocatalytic cleavage activity By similarity

Site

84 – 85

2

Cleavage; by autolysis

Natural variations

Natural variant

85

1

G → D in lexA3, resistant to cleavage.

Secondary structure

1

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202

Helix Strand Turn

Details...

Helix

6 – 22

17

Helix

28 – 34

7

Helix

40 – 52

13

Beta strand

55 – 58

4

Beta strand

60 – 64

5

Beta strand

66 – 68

3

Beta strand

76 – 79

4

Helix

91 – 93

3

Beta strand

94 – 98

5

Helix

102 – 104

3

Beta strand

105 – 107

3

Beta strand

111 – 114

4

Helix

121 – 123

3

Beta strand

130 – 134

5

Beta strand

144 – 149

6

Beta strand

152 – 161

10

Beta strand

164 – 168

5

Beta strand

177 – 180

4

Turn

181 – 183

3

Beta strand

186 – 197

12

Sequences

	Sequence		Length	Mass (Da)
	P0A7C2 [UniParc]. Last modified July 21, 1986. Version 1. Checksum: 7E8816A32C19EE71	FASTA	202	22,358
	10 20 30 40 50 60 MKALTARQQE VFDLIRDHIS QTGMPPTRAE IAQRLGFRSP NAAEEHLKAL ARKGVIEIVS 70 80 90 100 110 120 GASRGIRLLQ EEEEGLPLVG RVAAGEPLLA QQHIEGHYQV DPSLFKPNAD FLLRVSGMSM 130 140 150 160 170 180 KDIGIMDGDL LAVHKTQDVR NGQVVVARID DEVTVKRLKK QGNKVELLPE NSEFKPIVVD 190 200 LRQQSFTIEG LAVGVIRNGD WL

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Nucleotide sequence of the lexA gene of E. coli." Horii T., Ogawa T., Ogawa H. Cell 23:689-697(1981) [PubMed: 7013987] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Nucleotide sequence of the lexA gene of Escherichia coli K-12." Markham B.E., Little J.W., Mount D.W. Nucleic Acids Res. 9:4149-4161(1981) [PubMed: 6272195] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], MUTANT LEXA3. Strain: K12.
[3]	"Analysis of the Escherichia coli genome. IV. DNA sequence of the region from 89.2 to 92.8 minutes." Blattner F.R., Burland V.D., Plunkett G. III, Sofia H.J., Daniels D.L. Nucleic Acids Res. 21:5408-5417(1993) [PubMed: 8265357] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / MG1655 / ATCC 47076.
[4]	"The complete genome sequence of Escherichia coli K-12." Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., Shao Y. Science 277:1453-1474(1997) [PubMed: 9278503] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / MG1655 / ATCC 47076.
[5]	"Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110." Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T. Mol. Syst. Biol. 2:E1-E5(2006) [PubMed: 16738553] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[6]	"Genetic analysis of the LexA repressor: isolation and characterization of LexA(Def) mutant proteins." Oertel-Buchheit P., Lamerichs R.M., Schnarr M., Granger-Schnarr M. Mol. Gen. Genet. 223:40-48(1990) [PubMed: 2259342] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-93.
[7]	"Organization of the lexA gene of Escherichia coli and nucleotide sequence of the regulatory region." Miki T., Ebina Y., Kishi F., Nakazawa A. Nucleic Acids Res. 9:529-543(1981) [PubMed: 6261224] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-23.
[8]	Lilley P.E., Dixon N.E. Submitted (SEP-1992) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 195-202. Strain: K12.
[9]	"Purified lexA protein is a repressor of the recA and lexA genes." Little J.W., Mount D.W., Yanisch-Perron C.R. Proc. Natl. Acad. Sci. U.S.A. 78:4199-4203(1981) [PubMed: 7027255] [Abstract] Cited for: FUNCTION.
[10]	"Mechanism of action of the lexA gene product." Brent R., Ptashne M. Proc. Natl. Acad. Sci. U.S.A. 78:4204-4208(1981) [PubMed: 7027256] [Abstract] Cited for: FUNCTION.
[11]	"The amino-terminal domain of LexA repressor is alpha-helical but differs from canonical helix-turn-helix proteins: a two-dimensional 1H NMR study." Lamerichs R.M.J.N., Padilla A., Boelens R., Kaptein R., Ottleben G., Rueterjans H., Granger-Schnarr M., Oertel P., Schnarr M. Proc. Natl. Acad. Sci. U.S.A. 86:6863-6867(1989) [PubMed: 2780544] [Abstract] Cited for: STRUCTURE BY NMR.
[12]	"Solution structure of the LexA repressor DNA binding domain determined by 1H NMR spectroscopy." Fogh R.H., Ottleben G., Rueterjans H., Schnarr M., Boelens R., Kaptein R. EMBO J. 13:3936-3944(1994) [PubMed: 8076591] [Abstract] Cited for: STRUCTURE BY NMR.
[13]	"A model for the LexA repressor DNA complex." Knegtel R.M.A., Fogh R.H., Ottleben G., Rueterjans H., Dumoulin P., Schnarr M., Boelens R., Kaptein R. Proteins 21:226-236(1995) [PubMed: 7784426] [Abstract] Cited for: 3D-STRUCTURE MODELING.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

J01643 Genomic DNA. Translation: AAA24067.1.
U00006 Genomic DNA. Translation: AAC43137.1.
U00096 Genomic DNA. Translation: AAC77013.1.
AP009048 Genomic DNA. Translation: BAE78045.1.
L02362 Genomic DNA. Translation: AAA24068.1.

PIR

ILEC. A90808.

RefSeq

NP_418467.1. NC_000913.2.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1JHC	X-ray	2.00	A	68-202	[»]
1JHE	X-ray	2.50	A/B	68-202	[»]
1JHF	X-ray	1.80	A/B	1-202	[»]
1JHH	X-ray	2.10	A/B	1-202	[»]
1LEA	NMR	-	A	1-84	[»]
1LEB	NMR	-	A	1-84	[»]
1MVD	model	-	A/B	1-202	[»]
1QAA	model	-	A/B	1-202	[»]
3JSO	X-ray	2.29	A/B	1-202	[»]
3JSP	X-ray	2.90	A/B	1-202	[»]
3K3R	X-ray	3.20	E/F	1-202	[»]

ProteinModelPortal

P0A7C2.

SMR

P0A7C2. Positions 1-199.

ModBase

Search...

Protein-protein interaction databases

IntAct

P0A7C2. 3 interactions.

MINT

MINT-1314348.

Protein family/group databases

MEROPS

S24.001.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

EnsemblBacteria

EBESCT00000001049; EBESCP00000001049; EBESCG00000000865.
EBESCT00000018138; EBESCP00000017429; EBESCG00000017193.

GeneID

948544.

GenomeReviews

Gene locus JW4003 in contig AP009048_GR.
Gene locus b4043 in contig U00096_GR.

KEGG

ecj:JW4003.
eco:b4043.

PATRIC

32123623. VBIEscCol129921_4160.

Organism-specific databases

EchoBASE

EB0528.

EcoGene

EG10533. lexA.

Phylogenomic databases

eggNOG

COG1974.

GeneTree

EBGT00050000009171.

HOGENOM

HBG679610.

OMA

IAENPDF.

PhylomeDB

P0A7C2.

ProtClustDB

PRK00215.

Enzyme and pathway databases

BioCyc

EcoCyc:PD00205.

Gene expression databases

Genevestigator

P0A7C2.

Family and domain databases

HAMAP

MF_00015. LexA.
[Tree]

InterPro

IPR006199. LexA_DNA-bd_dom.
IPR006200. Pept_S24_LexA.
IPR006197. Peptidase_S24_LexA.
IPR019759. Peptidase_S24_S26.
IPR015927. Peptidase_S24_S26A/B/C.
IPR011056. Peptidase_S24_S26A/B/C_b-rbn.
IPR011991. WHTH_trsnscrt_rep_DNA-bd.
[Graphical view]

Gene3D

G3DSA:2.10.109.10. Pept_S24_S26_C. 1 hit.
G3DSA:1.10.10.10. Wing_hlx_DNA_bd. 1 hit.

KO

K01356.

Pfam

PF01726. LexA_DNA_bind. 1 hit.
PF00717. Peptidase_S24. 1 hit.
[Graphical view]

PRINTS

PR00726. LEXASERPTASE.

SUPFAM

SSF51306. Pept_S24_S26_C. 1 hit.

TIGRFAMs

TIGR00498. LexA. 1 hit.

ProtoNet

Search...

Entry information

Entry name

LEXA_ECOLI

Accession

Primary (citable) accession number: P0A7C2
Secondary accession number(s): P03033, Q2M6R1

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	July 21, 1986
Last modified:	January 25, 2012
This is version 69 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program