Reviewed, UniProtKB/Swiss-Prot Q1QMK3 (LEXA_NITHX)

Names and origin

Protein names

Recommended name:
    LexA repressor
    EC=3.4.21.88

Gene names

Name:	lexA
Ordered Locus Names:	Nham_1729

Organism

Nitrobacter hamburgensis (strain X14 / DSM 10229) [Complete proteome] [HAMAP]

Taxonomic identifier

323097 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Alphaproteobacteria › Rhizobiales › Bradyrhizobiaceae › Nitrobacter

Protein attributes

Sequence length	233 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Inferred from homology.

General annotation (Comments)

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.
Catalytic activity	Hydrolysis of Ala-|-Gly bond in repressor lexA. HAMAP MF_00015
Subunit structure	Homodimer By similarity.
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	Complete proteome
Gene Ontology (GO)
Biological process	DNA repair Inferred from electronic annotation. Source: HAMAP DNA replication Inferred from electronic annotation. Source: HAMAP SOS response Inferred from electronic annotation. Source: HAMAP negative regulation of transcription, DNA-dependent Inferred from electronic annotation. Source: HAMAP proteolysis Inferred from electronic annotation. Source: InterPro transcription Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	DNA binding Inferred from electronic annotation. Source: HAMAP serine-type endopeptidase activity Inferred from electronic annotation. Source: HAMAP
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 233	233	LexA repressor HAMAP MF_00015		PRO_1000001308
Regions
	DNA binding	26 – 46	21	H-T-H motif By similarity
Sites
	Active site	154	1	For autocatalytic cleavage activity By similarity
	Active site	192	1	For autocatalytic cleavage activity By similarity
	Site	119 – 120	2	Cleavage; by autolysis By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q1QMK3-1 [UniParc]. Last modified May 16, 2006. Version 1. Checksum: 0C4600113F22D5D0	FASTA	233	25,560
	10 20 30 40 50 60 MLTRKQYELL RFINERLKES GVPPSFDEMK DALDLRSKSG IHRLITALEE RGFIRRLPNR 70 80 90 100 110 120 ARAIEVIKLP EVAGNGGGRR GFTPSVIEGN LGKVRPSGGG VVDDAERPVA VPVMGRIAAG 130 140 150 160 170 180 TPIEALQTRS HTISVPPDML GSGEHYALEV RGDSMVEAGI LDGDMALIQR NETAETGDIV 190 200 210 220 230 VALIDDEEAT LKRFRRRGAS IALEPANTAY EVRILPPNRV QIQGKLIGIY RKY

References

[1]

"Complete sequence of chromosome of Nitrobacter hamburgensis X14." Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina del Rio T., Hammon N., Israni S., Dalin E., Tice H., Pitluck S., Chain P., Malfatti S., Shin M., Vergez L., Schmutz J., Larimer F., Land M. , Hauser L., Kyrpides N., Ivanova N., Ward B., Arp D., Klotz M., Stein L., O'Mullan G., Starkenburg S., Sayavedra L., Poret-Peterson A.T., Gentry M.E., Bruce D., Richardson P. Submitted (MAR-2006) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].

Cross-references

Sequence databases
EMBLGenBankDDBJ	CP000319 Genomic DNA. Translation: ABE62544.1.
RefSeq	YP_577004.1.
3D structure databases
ModBase	Search...
Protein family/group databases
MEROPS	S24.001.
Genome annotation databases
GeneID	4030348.
GenomeReviews	Gene locus Nham_1729 in contig CP000319_GR.
KEGG	nha:Nham_1729.
NMPDR	fig|323097.3.peg.2384.
Organism-specific databases
CMR	Search...
Phylogenomic databases
HOGENOM	Q1QMK3.
OMA	Q1QMK3. AILTFIR.
Enzyme and pathway databases
BioCyc	NHAM323097:NHAM_1729-MON.
Family and domain databases
HAMAP	MF_00015. [Tree]
InterPro	IPR006199. LexA_DNA_bd. IPR006200. Pept_S24_LexA. IPR006197. Peptidase_S24_LexA_cons-reg. IPR019759. Peptidase_S24_S26_cons-reg. IPR011056. Peptidase_S24_S26A/B/C_b-rbn. IPR011991. Wing_hlx_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.
Pfam	PF01726. LexA_DNA_bind. 1 hit. PF00717. Peptidase_S24. 1 hit. [Graphical view]
PRINTS	PR00726. LEXASERPTASE.
TIGRFAMs	TIGR00498. lexA. 1 hit.
ProtoNet	Search...

Entry information

Entry name

LEXA_NITHX

Accession

Primary (citable) accession number: Q1QMK3

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 15, 2008
Last sequence update:	May 16, 2006
Last modified:	June 16, 2009
This is version 24 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)