BTUB_CITFR
ID BTUB_CITFR Reviewed; 612 AA.
AC O52903;
DT 15-MAR-2005, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-1998, sequence version 1.
DT 03-AUG-2022, entry version 103.
DE RecName: Full=Vitamin B12 transporter BtuB {ECO:0000255|HAMAP-Rule:MF_01531};
DE AltName: Full=Cobalamin receptor {ECO:0000255|HAMAP-Rule:MF_01531};
DE AltName: Full=Outer membrane cobalamin translocator {ECO:0000255|HAMAP-Rule:MF_01531};
DE Flags: Precursor;
GN Name=btuB {ECO:0000255|HAMAP-Rule:MF_01531};
OS Citrobacter freundii.
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Citrobacter; Citrobacter freundii complex.
OX NCBI_TaxID=546;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC STRAIN=ATCC 8090 / DSM 30039 / JCM 1657 / LMG 3246 / NCTC 9750;
RA Letley D.P., Ward R.J., Glass R.E.;
RT "Cloning and chimeric analysis of Citrobacter freundii BtuB defines
RT residues essential for phage BF23 infection.";
RL Submitted (OCT-1996) to the EMBL/GenBank/DDBJ databases.
CC -!- FUNCTION: Involved in the active translocation of vitamin B12
CC (cyanocobalamin) across the outer membrane to the periplasmic space. It
CC derives its energy for transport by interacting with the trans-
CC periplasmic membrane protein TonB. {ECO:0000255|HAMAP-Rule:MF_01531}.
CC -!- SUBCELLULAR LOCATION: Cell outer membrane {ECO:0000255|HAMAP-
CC Rule:MF_01531}; Multi-pass membrane protein {ECO:0000255|HAMAP-
CC Rule:MF_01531}.
CC -!- SIMILARITY: Belongs to the TonB-dependent receptor family. BtuB (TC
CC 1.B.14.3.1) subfamily. {ECO:0000255|HAMAP-Rule:MF_01531}.
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DR EMBL; Y09059; CAA70262.1; -; Genomic_DNA.
DR PIR; S77723; S77723.
DR AlphaFoldDB; O52903; -.
DR SMR; O52903; -.
DR STRING; 1333848.CFNIH1_07425; -.
DR GO; GO:0009279; C:cell outer membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0046930; C:pore complex; IEA:UniProtKB-KW.
DR GO; GO:0015420; F:ABC-type vitamin B12 transporter activity; IEA:InterPro.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0015288; F:porin activity; IEA:UniProtKB-KW.
DR GO; GO:0006811; P:ion transport; IEA:UniProtKB-KW.
DR Gene3D; 2.170.130.10; -; 1.
DR Gene3D; 2.40.170.20; -; 1.
DR HAMAP; MF_01531; BtuB; 1.
DR InterPro; IPR010101; B12_transptr_BtuB.
DR InterPro; IPR039426; BtuB-like.
DR InterPro; IPR012910; Plug_dom.
DR InterPro; IPR037066; Plug_dom_sf.
DR InterPro; IPR000531; TonB-dep_rcpt_b-brl.
DR InterPro; IPR010916; TonB_box_CS.
DR InterPro; IPR036942; TonB_rcpt_b-brl_sf.
DR InterPro; IPR010917; TonB_rcpt_CS.
DR PANTHER; PTHR30069; PTHR30069; 1.
DR Pfam; PF07715; Plug; 1.
DR Pfam; PF00593; TonB_dep_Rec; 1.
DR TIGRFAMs; TIGR01779; TonB-B12; 1.
DR PROSITE; PS00430; TONB_DEPENDENT_REC_1; 1.
DR PROSITE; PS01156; TONB_DEPENDENT_REC_2; 1.
PE 3: Inferred from homology;
KW Calcium; Cell outer membrane; Ion transport; Membrane; Metal-binding;
KW Porin; Signal; TonB box; Transmembrane; Transmembrane beta strand;
KW Transport.
FT SIGNAL 1..20
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT CHAIN 21..612
FT /note="Vitamin B12 transporter BtuB"
FT /id="PRO_0000003478"
FT TRANSMEM 158..165
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 169..178
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 184..195
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 217..227
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 232..248
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 263..277
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 279..296
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 309..325
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 328..337
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 353..369
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 371..381
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 385..400
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 403..417
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 434..443
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 449..458
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 473..490
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 494..509
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 517..529
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 535..550
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 556..570
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 583..594
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT TRANSMEM 600..612
FT /note="Beta stranded"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT MOTIF 26..33
FT /note="TonB box"
FT MOTIF 595..612
FT /note="TonB C-terminal box"
FT BINDING 85
FT /ligand="cyanocob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:17439"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 92
FT /ligand="cyanocob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:17439"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 110..111
FT /ligand="cyanocob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:17439"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 199
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 211
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 213
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 213
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 215
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 215
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 249
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 250
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 250
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 261
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 309
FT /ligand="cyanocob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:17439"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 517
FT /ligand="cyanocob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:17439"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
FT BINDING 551
FT /ligand="cyanocob(III)alamin"
FT /ligand_id="ChEBI:CHEBI:17439"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01531"
SQ SEQUENCE 612 AA; 68125 MW; 1040A58DC318D63E CRC64;
MIKKSLLCTA LSVTAFSGWA QDTRPDTLVV TANRFQQPRS AVLAPITVVT RQDIDRWQST
SVNDVLRRLP GVDIAQYGGM GQNSSISIRG TNASHVLVLI DGVRLNLAGV SGAADLSQFP
VSLVQRIEYI RGPRSAVYGS DAIGGVVNII TTREKPGTEL TAGVGSNGYQ NYDVSTQQQL
GENTRVTLMG DYAYTKGFDV VAYGSTGSQA QPDKDGFLSK TLYGALEHNF SDTWSGFVRG
YGYDNRTNYD SYYSPGSPLL DTRKLYSQSW DAGLRFNGEL IQSQLVSSYS HSKDYNYDPD
YGRYDSSATL DEMKQYNVQW SNSIVVGHGN VGAGVDWQKQ TTEPGTGYVT DGYDQRNTGL
YLTGLQQLGD FTFEGAARSD DNSEFGRHGT WQTSAGWEFI EGYRFIASYG TSYKAPNLGQ
LHGYYGNSNL DPEQSKQWEG AFEGLTAGVN WRVSGYRNDI DDMIDYDPHT EKYFNEGKVR
IKGVEATANF DTGPLAHTLS YDMVDSRNAI TDKPLARRSK QQVKYQLDWQ VYDFDWGLTY
HYLGTRYDTD YVTYQPVKMG GVSLWDLAVS YPITSQLTVR GKIANRFDKD YETVYGYATA
GREYTLSGSY TF
