P04994 · EX7L_ECOLI
- ProteinExodeoxyribonuclease 7 large subunit
- GenexseA
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids456 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Bidirectionally degrades single-stranded DNA into large acid-insoluble oligonucleotides, which are then degraded further into small acid-soluble oligonucleotides. It can degrade 3' or 5' ss regions extending from the termini of duplex DNA molecules and displaced ss regions. It can also excise thymine dimers in vitro (Probable) (PubMed:22718974, PubMed:4602029, PubMed:4602030).
ssDNA-binding requires both subunits (PubMed:22718974).
Required for production of the mature 5'-end of retron Ec78 or Ec83 msDNA. Overproduction of this subunit in the absence of an equivalent quantity of the small subunit is toxic, causing cell elongation and chromosome fragmentation or loss; its toxicity is mostly suppressed by RecA (PubMed:26626352).
ssDNA-binding requires both subunits (PubMed:22718974).
Required for production of the mature 5'-end of retron Ec78 or Ec83 msDNA. Overproduction of this subunit in the absence of an equivalent quantity of the small subunit is toxic, causing cell elongation and chromosome fragmentation or loss; its toxicity is mostly suppressed by RecA (PubMed:26626352).
Catalytic activity
Cofactor
Note: Does not require a metal cofactor.
pH Dependence
Optimum pH is 7.8 to 7.9.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Cellular Component | exodeoxyribonuclease VII complex | |
Molecular Function | DNA binding | |
Molecular Function | exodeoxyribonuclease VII activity | |
Biological Process | DNA catabolic process | |
Biological Process | mismatch repair |
Keywords
- Molecular function
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameExodeoxyribonuclease 7 large subunit
- EC number
- Alternative names
Gene names
Organism names
- Organism
- Strains
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia
Accessions
- Primary accessionP04994
- Secondary accessions
Proteomes
Subcellular Location
Phenotypes & Variants
Disruption phenotype
No longer processes msDNA correctly (when retron Ec78 or Ec83 are expressed in the strain).
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 63 | About 10% ssDNA-binding by N-terminal domain. | ||||
Sequence: F → A | ||||||
Mutagenesis | 64-69 | About 20% ssDNA-binding by N-terminal domain. | ||||
Sequence: RNSNRR → ENSNEE | ||||||
Mutagenesis | 96 | About 50% ssDNA-binding by N-terminal domain. | ||||
Sequence: Q → A | ||||||
Mutagenesis | 155 | Loss of exonuclease activity, reduced ssDNA-binding. | ||||
Sequence: D → A | ||||||
Mutagenesis | 155 | Does not cleave Ec83 msDNA, not lethal on overexpression. | ||||
Sequence: D → N | ||||||
Mutagenesis | 177 | Wild-type exonuclease activity. | ||||
Sequence: Q → A | ||||||
Mutagenesis | 188 | Cleaves EC83 msDNA normally, reduced toxicity on overexpression. | ||||
Sequence: A → T | ||||||
Mutagenesis | 205 | Loss of exonuclease activity, still binds ssDNA. | ||||
Sequence: R → A | ||||||
Mutagenesis | 237 | Does not cleave Ec83 msDNA, 10-fold reduced toxicity on overexpression. | ||||
Sequence: G → R | ||||||
Mutagenesis | 238 | Loss of exonuclease activity, still binds ssDNA. | ||||
Sequence: H → A | ||||||
Mutagenesis | 241 | Loss of exonuclease activity, still binds ssDNA. | ||||
Sequence: D → A | ||||||
Mutagenesis | 246 | Wild-type exonuclease activity. | ||||
Sequence: D → A | ||||||
Mutagenesis | 250 | Wild-type exonuclease activity. | ||||
Sequence: D → A | ||||||
Mutagenesis | 255 | Wild-type exonuclease activity. | ||||
Sequence: T → A | ||||||
Mutagenesis | 397-456 | Loss of exonuclease activity. | ||||
Sequence: Missing |
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000197845 | 1-456 | Exodeoxyribonuclease 7 large subunit | |||
Sequence: MLPSQSPAIFTVSRLNQTVRLLLEHEMGQVWISGEISNFTQPASGHWYFTLKDDTAQVRCAMFRNSNRRVTFRPQHGQQVLVRANITLYEPRGDYQIIVESMQPAGEGLLQQKYEQLKAKLQAEGLFDQQYKKPLPSPAHCVGVITSKTGAALHDILHVLKRRDPSLPVIIYPAAVQGDDAPGQIVRAIELANQRNECDVLIVGRGGGSLEDLWSFNDERVARAIFTSRIPVVSAVGHETDVTIADFVADLRAPTPSAAAEVVSRNQQELLRQVQSTRQRLEMAMDYYLANRTRRFTQIHHRLQQQHPQLRLARQQTMLERLQKRMSFALENQLKRTGQQQQRLTQRLNQQNPQPKIHRAQTRIQQLEYRLAETLRAQLSATRERFGNAVTHLEAVSPLSTLARGYSVTTATDGNVLKKVKQVKAGEMLTTRLEDGWIESEVKNIQPVKKSRKKVH |
Proteomic databases
Interaction
Subunit
Heterooligomer composed of two different subunits with an approximate ratio of 4:1 for small to large subunit (Probable). Also estimated to have a 6:1 ration for small to large subunits (Probable).
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | P04994 | intQ P76168 | 3 | EBI-559703, EBI-559711 |
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 1-103 | Binds ssDNA, also required to bind the small subunit | ||||
Sequence: MLPSQSPAIFTVSRLNQTVRLLLEHEMGQVWISGEISNFTQPASGHWYFTLKDDTAQVRCAMFRNSNRRVTFRPQHGQQVLVRANITLYEPRGDYQIIVESMQ |
Domain
Predicted to have 4 domains. The N-terminus (about residues 1-103) binds ssDNA and is required to bind the small subunit; it probably has an OB-fold. The predicted catalytic domain is residues 104-266. Three alpha-helices are predicted in the C-terminal region (residues 267-301, 307-349 and 353-393), their removal singly or in pairs reduces small subunit-binding; none of the deletions have exonuclease activity. The extreme C-terminus (394-456) is required for exonuclease activity (PubMed:22718974).
The N-terminus (residues 1-257) at low levels does not confer processing of msDNA and at higher levels is lethal. Lethality of this fragment is not counteracted by the small subunit (PubMed:26626352).
The N-terminus (residues 1-257) at low levels does not confer processing of msDNA and at higher levels is lethal. Lethality of this fragment is not counteracted by the small subunit (PubMed:26626352).
Sequence similarities
Belongs to the XseA family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length456
- Mass (Da)51,832
- Last updated1997-11-01 v2
- ChecksumA5E5B138C54A7D27
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 67 | in Ref. 1; AAA24766 | ||||
Sequence: N → S |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
J02599 EMBL· GenBank· DDBJ | AAA24766.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U00096 EMBL· GenBank· DDBJ | AAC75562.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AP009048 EMBL· GenBank· DDBJ | BAA16396.1 EMBL· GenBank· DDBJ | Genomic DNA |