P0A9E0 · ARAC_ECOLI
- ProteinArabinose operon regulatory protein
- GenearaC
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids292 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Transcription factor that regulates the expression of several genes involved in the transport and metabolism of L-arabinose (PubMed:1447222, PubMed:2231717, PubMed:2962192, PubMed:328165, PubMed:4362626, PubMed:6251457, PubMed:6319708).
Functions both as a positive and a negative regulator (PubMed:328165, PubMed:6251457).
In the presence of arabinose, activates the expression of the araBAD, araE, araFGH and araJ promoters (PubMed:1447222, PubMed:2231717, PubMed:2962192, PubMed:328165, PubMed:4362626, PubMed:6251457, PubMed:6319708).
In the absence of arabinose, negatively regulates the araBAD operon (PubMed:6251457).
Represses its own transcription (PubMed:328165). Acts by binding directly to DNA (PubMed:1447222, PubMed:2531226, PubMed:2962192, PubMed:4943786, PubMed:6251457).
Functions both as a positive and a negative regulator (PubMed:328165, PubMed:6251457).
In the presence of arabinose, activates the expression of the araBAD, araE, araFGH and araJ promoters (PubMed:1447222, PubMed:2231717, PubMed:2962192, PubMed:328165, PubMed:4362626, PubMed:6251457, PubMed:6319708).
In the absence of arabinose, negatively regulates the araBAD operon (PubMed:6251457).
Represses its own transcription (PubMed:328165). Acts by binding directly to DNA (PubMed:1447222, PubMed:2531226, PubMed:2962192, PubMed:4943786, PubMed:6251457).
Activity regulation
Arabinose converts the repressor form of AraC to the activator form to regulate the araBAD promoter (PubMed:2962192, PubMed:3279415).
In the absence of arabinose, AraC binds to the araO2 and araI1 half-sites in the promoter region of the araBAD operon, leading to the formation of a DNA loop that blocks access of RNA polymerase to the promoter. In the presence of arabinose and the cyclic AMP receptor protein (CRP), it binds to the adjacent half-sites araI1 and araI2, leading to the binding of RNA polymerase to the promoter region and transcription of the araBAD operon (PubMed:2962192, PubMed:3279415).
AraI1 acts as a switch mechanism allowing both the repressor and the activator forms of AraC protein to regulate the araBAD promoter (PubMed:2962192, PubMed:3279415).
Inhibited by D-fucose, which binds competitively to the same site on the protein (PubMed:9367758).
In the absence of arabinose, AraC binds to the araO2 and araI1 half-sites in the promoter region of the araBAD operon, leading to the formation of a DNA loop that blocks access of RNA polymerase to the promoter. In the presence of arabinose and the cyclic AMP receptor protein (CRP), it binds to the adjacent half-sites araI1 and araI2, leading to the binding of RNA polymerase to the promoter region and transcription of the araBAD operon (PubMed:2962192, PubMed:3279415).
AraI1 acts as a switch mechanism allowing both the repressor and the activator forms of AraC protein to regulate the araBAD promoter (PubMed:2962192, PubMed:3279415).
Inhibited by D-fucose, which binds competitively to the same site on the protein (PubMed:9367758).
Features
Showing features for binding site, dna binding.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 8 | alpha-L-arabinopyanose (UniProtKB | ChEBI) | ||||
Sequence: P | ||||||
Binding site | 24 | alpha-L-arabinopyanose (UniProtKB | ChEBI) | ||||
Sequence: T | ||||||
Binding site | 38 | alpha-L-arabinopyanose (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 82 | alpha-L-arabinopyanose (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 93 | alpha-L-arabinopyanose (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
DNA binding | 198-219 | H-T-H motif | ||||
Sequence: ASVAQHVCLSPSRLSHLFRQQL | ||||||
DNA binding | 246-269 | H-T-H motif | ||||
Sequence: IATVGRNVGFDDQLYFSRVFKKCT |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytosol | |
Cellular Component | protein-DNA complex | |
Molecular Function | DNA-binding transcription repressor activity | |
Molecular Function | identical protein binding | |
Molecular Function | transcription cis-regulatory region binding | |
Biological Process | arabinose catabolic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameArabinose operon regulatory protein
- Alternative names
Gene names
Organism names
- Organism
- Strains
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia
Accessions
- Primary accessionP0A9E0
- Secondary accessions
Proteomes
Subcellular Location
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 31 | Eliminates the self-association, but does not affect regulation properties of the protein. | ||||
Sequence: Y → V | ||||||
Mutagenesis | 209 | Defective in DNA binding. | ||||
Sequence: S → A | ||||||
Mutagenesis | 213 | Defective in DNA binding. | ||||
Sequence: H → A or Y | ||||||
Mutagenesis | 257 | Does not bind DNA. | ||||
Sequence: D → A | ||||||
Mutagenesis | 258 | Defective in DNA binding. | ||||
Sequence: Q → A | ||||||
Mutagenesis | 262 | Does not affect DNA binding. | ||||
Sequence: S → A |
Chemistry
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000194499 | 1-292 | Arabinose operon regulatory protein | |||
Sequence: MAEAQNDPLLPGYSFNAHLVAGLTPIEANGYLDFFIDRPLGMKGYILNLTIRGQGVVKNQGREFVCRPGDILLFPPGEIHHYGRHPEAREWYHQWVYFRPRAYWHEWLNWPSIFANTGFFRPDEAHQPHFSDLFGQIINAGQGEGRYSELLAINLLEQLLLRRMEAINESLHPPMDNRVREACQYISDHLADSNFDIASVAQHVCLSPSRLSHLFRQQLGISVLSWREDQRISQAKLLLSTTRMPIATVGRNVGFDDQLYFSRVFKKCTGASPSEFRAGCEEKVNDVAVKLS |
Proteomic databases
Expression
Induction
Negatively autoregulated (PubMed:3279415, PubMed:328165, PubMed:6377308).
Autoregulation is either greatly reduced or nonexistent immediately after the addition of L-arabinose (PubMed:6377308).
Transcription is stimulated by CRP in the presence of cAMP (PubMed:328165, PubMed:6377308).
Autoregulation is either greatly reduced or nonexistent immediately after the addition of L-arabinose (PubMed:6377308).
Transcription is stimulated by CRP in the presence of cAMP (PubMed:328165, PubMed:6377308).
Gene expression databases
Interaction
Subunit
Homodimer.
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | P0A9E0 | araC P0A9E0 | 3 | EBI-1113479, EBI-1113479 | |
BINARY | P0A9E0 | xerC P0A8P6 | 3 | EBI-1113479, EBI-1133806 |
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 180-279 | HTH araC/xylS-type | ||||
Sequence: REACQYISDHLADSNFDIASVAQHVCLSPSRLSHLFRQQLGISVLSWREDQRISQAKLLLSTTRMPIATVGRNVGFDDQLYFSRVFKKCTGASPSEFRAG |
Domain
Contains an N-terminal domain that binds arabinose and mediates dimerization, an inter-domain linker region, and a C-terminal domain that binds DNA (PubMed:26800223, PubMed:9103202, PubMed:9367758).
Arabinose is bound within a beta barrel and is completely buried by the N-terminal arm of the protein (PubMed:9103202).
The DNA-binding domain contains seven helices arranged in two semi-independent subdomains, each containing one helix-turn-helix DNA binding motif, joined by a 19 residue central helix (PubMed:19422057).
Arabinose is bound within a beta barrel and is completely buried by the N-terminal arm of the protein (PubMed:9103202).
The DNA-binding domain contains seven helices arranged in two semi-independent subdomains, each containing one helix-turn-helix DNA binding motif, joined by a 19 residue central helix (PubMed:19422057).
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length292
- Mass (Da)33,384
- Last updated1986-07-21 v1
- ChecksumC5A737E285A4ECC6
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 7 | in Ref. 7; AAA23468 | ||||
Sequence: D → E |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
V00256 EMBL· GenBank· DDBJ | CAA23507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
V00259 EMBL· GenBank· DDBJ | CAA23508.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
J01641 EMBL· GenBank· DDBJ | AAA23466.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
U00096 EMBL· GenBank· DDBJ | AAC73175.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AP009048 EMBL· GenBank· DDBJ | BAB96633.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
K01303 EMBL· GenBank· DDBJ | AAA23468.1 EMBL· GenBank· DDBJ | Genomic DNA |