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    btuB cobalamin outer membrane transporter [ Escherichia coli str. K-12 substr. MG1655 ]

    Gene ID: 948468, updated on 3-Dec-2024

    Summary

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    Official Symbol
    btuB
    Official Full Name
    cobalamin outer membrane transporter
    Primary source
    ECOCYC:EG10126
    Locus tag
    b3966
    See related
    ASAP:ABE-0012987
    Gene type
    protein coding
    RefSeq status
    PROVISIONAL
    Organism
    Escherichia coli str. K-12 substr. MG1655 (strain: K-12, substrain: MG1655)
    Lineage
    Bacteria; Pseudomonadota; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia
    Also known as
    bfe; cer; ECK3958
    Summary
    BtuB translation is regulated by adenosylcobalamin binding directly to btuB mRNA, a B12-responsive riboswitch. [More information is available at EcoGene: EG10126]. BtuB is an outer membrane porin that mediates high affinity binding and TonB- dependent active transport of vitamin B12 (cyanocobalamin) across the outer membrane. [More information is available at EcoCyc: EG10126].
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    Genomic context

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    Sequence:
    NC_000913.3 (4163639..4165483)

    NC_000913.3Genomic Context describing neighboring genes Neighboring gene DNA-binding transcriptional repressor FabR Neighboring gene DUF1422 domain-containing inner membrane protein YijD Neighboring gene tRNA m(5)U54 methyltransferase Neighboring gene glutamate racemase Neighboring gene 16S ribosomal RNA Neighboring gene tRNA-Glu

    Genomic regions, transcripts, and products

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    Genomic Sequence:
    NC_000913.3

    Go to nucleotide: Graphics FASTA GenBank

    Bibliography

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    Related articles in PubMed

    1. Genetic control by a metabolite binding mRNA. Nahvi A, et al. Chem Biol, 2002 Sep. PMID 12323379
    2. A requirement for calcium in the transport of cobalamin across the outer membrane of Escherichia coli. Bradbeer C, et al. J Biol Chem, 1986 Feb 25. PMID 3512539
    3. Analysis of btuB receptor function by use of nonsense suppression. Hunter MG, et al. J Bacteriol, 1982 Sep. PMID 7050093, Free PMC Article
    4. Sequences of the Escherichia coli BtuB protein essential for its insertion and function in the outer membrane. Lathrop JT, et al. J Bacteriol, 1995 Dec. PMID 7592472, Free PMC Article
    5. Structure-function analysis of the vitamin B12 receptor of Escherichia coli by means of informational suppression. Hufton SE, et al. Mol Microbiol, 1995 Jan. PMID 7746157

    See all (88) citations in PubMed

    GeneRIFs: Gene References Into Functions

    What's a GeneRIF?
    1. Riboswitch and small RNAs modulate btuB translation initiation in Escherichia coli and trigger distinct mRNA regulatory mechanisms.
      Title: Riboswitch and small RNAs modulate btuB translation initiation in Escherichia coli and trigger distinct mRNA regulatory mechanisms.
    2. HDX-MS performed on BtuB in E. coli outer membranes delineates the luminal domain's allostery and unfolding upon B12 and TonB binding.
      Title: HDX-MS performed on BtuB in E. coli outer membranes delineates the luminal domain's allostery and unfolding upon B12 and TonB binding.
    3. The btuB riboswitch modulates the formation of a tertiary structure to perform metabolite sensing and regulate gene expression.
      Title: A kissing loop is important for btuB riboswitch ligand sensing and regulatory control.
    4. The lack of a AdoCbl-induced conformational switch experienced by the btuB riboswitch in the absence of Mg(2+) indicates a crucial role played by Mg(2+) for defining an active conformation of the riboswitch.
      Title: Mg(2+)-induced conformational changes in the btuB riboswitch from E. coli.
    5. Through biological and biochemical analysis, authors have demonstrated the GadX can directly interact with btuB promoter and affect the expression of btuB.
      Title: Repression of btuB gene transcription in Escherichia coli by the GadX protein.
    6. A portion of the N-terminal region of BtuB which occupies the lumen of the BtuB barrel denatures prior to the unfolding of the BtuB barrel, so that the free energy of folding for the N-terminus is smaller than that typically seen for globular proteins.
      Title: The N-terminal domain of a TonB-dependent transporter undergoes a reversible stepwise denaturation.
    7. analysis of the conformation of BtuB by electron paramagnetic resonance
      Title: Molecular origin of electron paramagnetic resonance line shapes on β-barrel membrane proteins: the local solvation environment modulates spin-label configuration.
    8. Data describe the effect of calcium ions on the conformation of the extracellular loops of BtuB and their possible role in B12 binding.
      Title: The effect of calcium on the conformation of cobalamin transporter BtuB.
    9. High concentrations of stabilizing solutes, such as those used to generate membrane protein crystals, result in a more compact and ordered state of the protein than is seen under more physiological conditions.
      Title: Solutes alter the conformation of the ligand binding loops in outer membrane transporters.
    10. the role of the TonB-ExbB-ExbD complex, potentiated by the proton motive force, is to reduce the affinity of the Cbl-binding site, thus increasing the rate of Cbl release into the periplasmic space
      Title: Observations on the calcium dependence and reversibility of cobalamin transport across the outer membrane of Escherichia coli.
    Submit: New GeneRIF Correction See all GeneRIFs (18)

    Interactions

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    Products Interactant Other Gene Complex Source Pubs Description

    General gene information

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    Gene Ontology Provided by EcoCyc

    Function Evidence Code Pubs
    enables ABC-type vitamin B12 transporter activity IEA
    Inferred from Electronic Annotation
    more info
    		  
    enables calcium ion binding IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    enables metal ion binding IEA
    Inferred from Electronic Annotation
    more info
    		  
    enables porin activity IEA
    Inferred from Electronic Annotation
    more info
    		  
    enables protein binding IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    enables protein binding IPI
    Inferred from Physical Interaction
    more info
    		 PubMed 
    enables protein domain specific binding IPI
    Inferred from Physical Interaction
    more info
    		 PubMed 
    enables vitamin transmembrane transporter activity IEA
    Inferred from Electronic Annotation
    more info
    		  
    Process Evidence Code Pubs
    involved_in cobalamin transport IBA
    Inferred from Biological aspect of Ancestor
    more info
    		  
    acts_upstream_of_or_within cobalamin transport IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    involved_in cobalamin transport IEA
    Inferred from Electronic Annotation
    more info
    		  
    acts_upstream_of_or_within cobalamin transport IMP
    Inferred from Mutant Phenotype
    more info
    		 PubMed 
    involved_in cobalamin transport NAS
    Non-traceable Author Statement
    more info
    		 PubMed 
    acts_upstream_of monoatomic ion transmembrane transport IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    involved_in monoatomic ion transport IEA
    Inferred from Electronic Annotation
    more info
    		  
    involved_in vitamin transmembrane transport IEA
    Inferred from Electronic Annotation
    more info
    		  
    Component Evidence Code Pubs
    is_active_in cell outer membrane IBA
    Inferred from Biological aspect of Ancestor
    more info
    		  
    located_in cell outer membrane IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    located_in cell outer membrane IEA
    Inferred from Electronic Annotation
    more info
    		  
    located_in cell outer membrane NAS
    Non-traceable Author Statement
    more info
    		 PubMed 
    located_in membrane IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    located_in membrane IEA
    Inferred from Electronic Annotation
    more info
    		  
    part_of pore complex IEA
    Inferred from Electronic Annotation
    more info
    		  
    part_of transmembrane transporter complex NAS
    Non-traceable Author Statement
    more info
    		 PubMed 

    General protein information

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    Preferred Names
    cobalamin outer membrane transporter

    NCBI Reference Sequences (RefSeq)

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    Genome Annotation

    The following sections contain reference sequences that belong to a specific genome build. Explain

    Reference assembly

    Genomic

    1. NC_000913.3 Reference assembly

      Range
      4163639..4165483
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    mRNA and Protein(s)

    1. NP_418401.1 cobalamin outer membrane transporter [Escherichia coli str. K-12 substr. MG1655]

      See identical proteins and their annotated locations for NP_418401.1

      Status: PROVISIONAL

      UniProtKB/TrEMBL
      A0A2H4TS82
      Conserved Domains (1) summary
      PRK10641
      Location:1 → 614
      btuB; TonB-dependent vitamin B12 receptor BtuB
    Nucleotide Protein
    Heading Accession and Version

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