Annotations: 1JHF

Domain Annotation: SCOP/SCOPe Classification SCOP Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1jhfa1	All alpha proteins	DNA/RNA-binding 3-helical bundle	'Winged helix' DNA-binding domain	LexA repressor, N-terminal DNA-binding domain	LexA repressor, N-terminal DNA-binding domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
A	d1jhfa2	All beta proteins	LexA/Signal peptidase	LexA/Signal peptidase	LexA-related	LexA C-terminal domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
B	d1jhfb_	All beta proteins	LexA/Signal peptidase	LexA/Signal peptidase	LexA-related	LexA C-terminal domain	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	LexA repressor DNA-binding domain-like	8002595	4000150	SCOP2 (2022-06-29)
A	SCOP2 Family	LexA endopeptidase domain-like	8002598	4000321	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Winged helix DNA-binding domain	8002596	3000034	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	LexA/Signal peptidase-like	8002599	3000103	SCOP2 (2022-06-29)
B	SCOP2B Superfamily	LexA/Signal peptidase-like	8002599	3000103	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	Peptidase_S24	e1jhfA1	A: beta barrels	X: SH3	H: LexA/Signal peptidase (From Topology)	T: LexA/Signal peptidase	F: Peptidase_S24	ECOD (1.6)
A	LexA_DNA_bind	e1jhfA2	A: alpha arrays	X: HTH	H: HTH	T: winged	F: LexA_DNA_bind	ECOD (1.6)
B	Peptidase_S24	e1jhfB1	A: beta barrels	X: SH3	H: LexA/Signal peptidase (From Topology)	T: LexA/Signal peptidase	F: Peptidase_S24	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	2.10.109.10	Mainly Beta	Ribbon	Umud Fragment, subunit A	Umud Fragment, subunit A	CATH (4.3.0)
A	1.10.10.10	Mainly Alpha	Orthogonal Bundle	Arc Repressor Mutant, subunit A	Winged helix-like DNA-binding domain superfamily/Winged helix DNA-binding domain	CATH (4.3.0)
B	2.10.109.10	Mainly Beta	Ribbon	Umud Fragment, subunit A	Umud Fragment, subunit A	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF01726	LexA DNA binding domain (LexA_DNA_bind)	LexA DNA binding domain	This is the DNA binding domain of the LexA SOS regulon repressor which prevents expression of DNA repair proteins. The aligned region contains a variant form of the helix-turn-helix DNA binding motif [1]. This domain is found associated with Pfam:P ...	This is the DNA binding domain of the LexA SOS regulon repressor which prevents expression of DNA repair proteins. The aligned region contains a variant form of the helix-turn-helix DNA binding motif [1]. This domain is found associated with Pfam:PF00717 the auto-proteolytic domain of LexA EC:3.4.21.88.	Domain
A, B	PF00717	Peptidase S24-like (Peptidase_S24)	Peptidase S24-like	-	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	LEXA REPRESSOR	DNA binding binding organic cyclic compound binding nucleic acid binding sequence-specific DNA binding sequence-specific double-stranded DNA binding transcription cis-regulatory region binding double-stranded DNA binding transcription regulatory region nucleic acid binding peptidase activity catalytic activity, acting on a protein serine hydrolase activity serine-type peptidase activity hydrolase activity DNA binding binding organic cyclic compound binding nucleic acid binding sequence-specific DNA binding sequence-specific double-stranded DNA binding transcription cis-regulatory region binding double-stranded DNA binding transcription regulatory region nucleic acid binding peptidase activity catalytic activity, acting on a protein serine hydrolase activity serine-type peptidase activity hydrolase activity serine-type endopeptidase activity catalytic activity endopeptidase activity identical protein binding protein binding transcription regulator activity DNA-binding transcription repressor activity DNA-binding transcription factor activity	cellular response to stimulus cellular response to stress response to stimulus DNA damage response response to stress cellular process regulation of cellular process negative regulation of biological process negative regulation of nitrogen compound metabolic process negative regulation of cellular metabolic process regulation of primary metabolic process negative regulation of RNA biosynthetic process nucleobase-containing compound metabolic process regulation of nitrogen compound metabolic process cellular response to stimulus cellular response to stress response to stimulus DNA damage response response to stress cellular process regulation of cellular process negative regulation of biological process negative regulation of nitrogen compound metabolic process negative regulation of cellular metabolic process regulation of primary metabolic process negative regulation of RNA biosynthetic process nucleobase-containing compound metabolic process regulation of nitrogen compound metabolic process DNA-templated transcription regulation of RNA metabolic process heterocycle metabolic process organic substance biosynthetic process negative regulation of nucleobase-containing compound metabolic process regulation of nucleobase-containing compound metabolic process negative regulation of DNA-templated transcription regulation of biological process cellular metabolic process negative regulation of metabolic process cellular nitrogen compound metabolic process primary metabolic process regulation of cellular metabolic process negative regulation of cellular biosynthetic process organic cyclic compound metabolic process regulation of gene expression biosynthetic process aromatic compound biosynthetic process negative regulation of macromolecule biosynthetic process organic cyclic compound biosynthetic process metabolic process regulation of macromolecule biosynthetic process macromolecule metabolic process regulation of DNA-templated transcription regulation of metabolic process negative regulation of RNA metabolic process cellular biosynthetic process RNA metabolic process RNA biosynthetic process nucleic acid biosynthetic process organic substance metabolic process negative regulation of cellular process nitrogen compound metabolic process regulation of RNA biosynthetic process negative regulation of macromolecule metabolic process regulation of biosynthetic process biological regulation regulation of macromolecule metabolic process nucleobase-containing compound biosynthetic process heterocycle biosynthetic process gene expression macromolecule biosynthetic process nucleic acid metabolic process regulation of cellular biosynthetic process negative regulation of biosynthetic process cellular aromatic compound metabolic process DNA metabolic process DNA replication DNA repair response to extracellular stimulus SOS response response to external stimulus cell communication cellular response to extracellular stimulus cellular response to external stimulus organonitrogen compound metabolic process proteolysis protein metabolic process	intracellular anatomical structure cytoplasm cellular anatomical entity cytosol protein-containing complex protein-DNA complex

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR015927	Peptidase S24/S26A/S26B/S26C	Domain
A, B	IPR036388	Winged helix-like DNA-binding domain superfamily	Homologous Superfamily
A, B	IPR036390	Winged helix DNA-binding domain superfamily	Homologous Superfamily
A, B	IPR006199	LexA repressor, DNA-binding domain	Domain
A, B	IPR039418	LexA-like	Domain
A, B	IPR006200	Transcription regulator LexA	Family
A, B	IPR036286	LexA/Signal peptidase-like superfamily	Homologous Superfamily
A, B	IPR006197	Peptidase S24, LexA-like	Family

Structure Motif Annotation: Mechanism and Catalytic Site Atlas M-CSA Database Homepage

Chains	Enzyme Name	Description	Catalytic Residues
A	repressor LexA M-CSA #724	LexA repressor (LexA) from Escherichia coli hydrolyses the specific peptide bond between Alanine and Glycine residues. It is of the peptidase S24 family. It can take two conformations; cleavable and non cleavable. In the non cleavable conformer, the Ala 84 - Gly 85 peptide bond lies about 20 angstroms away from the active site. In the cleavable conformer, part of the protein, the Ala 84 - Gly 85 peptide bond lies directly adjacent to the active site. In this case, LexA will cleave itself and become denatured. This function allows LexA to control the SOS response of E. coli to conditions that damage DNA or inhibit DNA replication.	Defined by 4 residues: MET:A-118SER:A-119GLU:A-152LYS:A-156 \| Explore in 3D: M-CSA Motif Definition Search M-CSA Motif EC: 3.4.21.88 (PDB Primary Data) Search M-CSA Motif + EC 3.4.21.88

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.