P0A9E0 · ARAC_ECOLI

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).

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).

Features

Showing features for binding site, dna binding.

TypeIDPosition(s)Description
Binding site8alpha-L-arabinopyanose (UniProtKB | ChEBI)
Binding site24alpha-L-arabinopyanose (UniProtKB | ChEBI)
Binding site38alpha-L-arabinopyanose (UniProtKB | ChEBI)
Binding site82alpha-L-arabinopyanose (UniProtKB | ChEBI)
Binding site93alpha-L-arabinopyanose (UniProtKB | ChEBI)
DNA binding198-219H-T-H motif
DNA binding246-269H-T-H motif

GO annotations

AspectTerm
Cellular Componentcytosol
Cellular Componentprotein-DNA complex
Molecular FunctionDNA-binding transcription repressor activity
Molecular Functionidentical protein binding
Molecular Functiontranscription cis-regulatory region binding
Biological Processarabinose catabolic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    Arabinose operon regulatory protein
  • Alternative names
    • HTH-type transcriptional regulator AraC

Gene names

    • Name
      araC
    • Ordered locus names
      b0064, JW0063

Organism names

  • Taxonomic identifier
  • Strains
    • B/R
    • K12
    • K12 / MG1655 / ATCC 47076
    • K12 / W3110 / ATCC 27325 / DSM 5911
  • Taxonomic lineage
    Bacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Enterobacteriaceae > Escherichia

Accessions

  • Primary accession
    P0A9E0
  • Secondary accessions
    • P03021
    • Q47056

Proteomes

Subcellular Location

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis31Eliminates the self-association, but does not affect regulation properties of the protein.
Mutagenesis209Defective in DNA binding.
Mutagenesis213Defective in DNA binding.
Mutagenesis257Does not bind DNA.
Mutagenesis258Defective in DNA binding.
Mutagenesis262Does not affect DNA binding.

Chemistry

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00001944991-292Arabinose operon regulatory protein

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).

Gene expression databases

Interaction

Subunit

Homodimer.

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntact
BINARY P0A9E0araC P0A9E03EBI-1113479, EBI-1113479
BINARY P0A9E0xerC P0A8P63EBI-1113479, EBI-1133806

Protein-protein interaction databases

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain180-279HTH araC/xylS-type

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).

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    292
  • Mass (Da)
    33,384
  • Last updated
    1986-07-21 v1
  • Checksum
    C5A737E285A4ECC6
MAEAQNDPLLPGYSFNAHLVAGLTPIEANGYLDFFIDRPLGMKGYILNLTIRGQGVVKNQGREFVCRPGDILLFPPGEIHHYGRHPEAREWYHQWVYFRPRAYWHEWLNWPSIFANTGFFRPDEAHQPHFSDLFGQIINAGQGEGRYSELLAINLLEQLLLRRMEAINESLHPPMDNRVREACQYISDHLADSNFDIASVAQHVCLSPSRLSHLFRQQLGISVLSWREDQRISQAKLLLSTTRMPIATVGRNVGFDDQLYFSRVFKKCTGASPSEFRAGCEEKVNDVAVKLS

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict7in Ref. 7; AAA23468

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
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

Genome annotation databases

Similar Proteins

Disclaimer

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