ID   MRPB_ALKPO              Reviewed;         144 AA.
AC   Q9RGZ4; D3FXI1;
DT   13-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   03-AUG-2022, entry version 81.
DE   RecName: Full=Na(+)/H(+) antiporter subunit B;
DE   AltName: Full=Mrp complex subunit B;
DE   AltName: Full=Multiple resistance and pH homeostasis protein B;
GN   Name=mrpB; OrderedLocusNames=BpOF4_13205;
OS   Alkalihalophilus pseudofirmus (strain ATCC BAA-2126 / JCM 17055 / OF4)
OS   (Bacillus pseudofirmus).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Bacillaceae; Alkalihalophilus.
OX   NCBI_TaxID=398511;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND CHARACTERIZATION.
RX   PubMed=11356194; DOI=10.1016/s0014-5793(01)02417-6;
RA   Ito M., Guffanti A.A., Krulwich T.A.;
RT   "Mrp-dependent Na(+)/H(+) antiporters of Bacillus exhibit characteristics
RT   that are unanticipated for completely secondary active transporters.";
RL   FEBS Lett. 496:117-120(2001).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-2126 / JCM 17055 / OF4;
RX   PubMed=21951522; DOI=10.1111/j.1462-2920.2011.02591.x;
RA   Janto B., Ahmed A., Ito M., Liu J., Hicks D.B., Pagni S., Fackelmayer O.J.,
RA   Smith T.A., Earl J., Elbourne L.D., Hassan K., Paulsen I.T., Kolsto A.B.,
RA   Tourasse N.J., Ehrlich G.D., Boissy R., Ivey D.M., Li G., Xue Y., Ma Y.,
RA   Hu F.Z., Krulwich T.A.;
RT   "Genome of alkaliphilic Bacillus pseudofirmus OF4 reveals adaptations that
RT   support the ability to grow in an external pH range from 7.5 to 11.4.";
RL   Environ. Microbiol. 13:3289-3309(2011).
RN   [3]
RP   CHARACTERIZATION, AND PROBABLE FUNCTION IN ELECTROGENIC ANTIPORTER
RP   ACTIVITY.
RX   PubMed=17293423; DOI=10.1128/jb.00021-07;
RA   Swartz T.H., Ito M., Ohira T., Natsui S., Hicks D.B., Krulwich T.A.;
RT   "Catalytic properties of Staphylococcus aureus and Bacillus members of the
RT   secondary cation/proton antiporter-3 (Mrp) family are revealed by an
RT   optimized assay in an Escherichia coli host.";
RL   J. Bacteriol. 189:3081-3090(2007).
CC   -!- FUNCTION: Mnh complex is a Na(+)Li(+)/H(+) antiporter involved in Na(+)
CC       and/or Li(+) excretion and Na(+) resistance. Na(+)/H(+) antiport
CC       consumes a transmembrane electrical potential, and is thus inferred to
CC       be electrogenic. Does not transport K(+), Ca(2+) or Mg(2+).
CC   -!- SUBUNIT: Forms a heterooligomeric complex that consists of seven
CC       subunits: MrpA, MrpB, MrpC, MrpD, MrpE, MrpF and MrpG. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000305}; Multi-pass membrane
CC       protein {ECO:0000305}.
CC   -!- MISCELLANEOUS: Mrp-dependent antiport apparently occurs by a secondary,
CC       proton motive force-dependent mechanism, but the similarity of several
CC       Mrp proteins to membrane-embedded subunits of energy-coupled NADH
CC       dehydrogenase complexes raises the possibility that there is a capacity
CC       for electron transport that could provide a primary energy coupling
CC       option for Mrp functions.
CC   -!- SIMILARITY: Belongs to the CPA3 antiporters (TC 2.A.63) subunit B
CC       family. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; AF097740; AAF21813.1; -; Genomic_DNA.
DR   EMBL; CP001878; ADC50692.1; -; Genomic_DNA.
DR   RefSeq; WP_012958055.1; NC_013791.2.
DR   AlphaFoldDB; Q9RGZ4; -.
DR   SMR; Q9RGZ4; -.
DR   STRING; 398511.BpOF4_13205; -.
DR   EnsemblBacteria; ADC50692; ADC50692; BpOF4_13205.
DR   KEGG; bpf:BpOF4_13205; -.
DR   eggNOG; COG2111; Bacteria.
DR   HOGENOM; CLU_101659_1_0_9; -.
DR   OMA; HPGFLMP; -.
DR   OrthoDB; 1962104at2; -.
DR   Proteomes; UP000001544; Chromosome.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0015297; F:antiporter activity; IEA:UniProtKB-KW.
DR   GO; GO:0006814; P:sodium ion transport; IEA:UniProtKB-KW.
DR   InterPro; IPR007182; MnhB.
DR   Pfam; PF04039; MnhB; 1.
PE   1: Evidence at protein level;
KW   Antiport; Cell membrane; Hydrogen ion transport; Ion transport; Membrane;
KW   Reference proteome; Sodium; Sodium transport; Transmembrane;
KW   Transmembrane helix; Transport.
FT   CHAIN           1..144
FT                   /note="Na(+)/H(+) antiporter subunit B"
FT                   /id="PRO_0000088863"
FT   TRANSMEM        9..31
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        41..58
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        75..97
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        117..139
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   144 AA;  15844 MW;  B59A8F7504F049BD CRC64;
     MKNLKSNDVL LHTLTRVVTF IILAFSVYLF FAGHNNPGGG FIGGLMTASA LLLMYLGFDM
     RSIKKAIPFD FTKMIAFGLL IAIFTGFGGL LVGDPYLTQY FEYYQIPILG ETELTTALPF
     DLGIYLVVIG IALTIILTIA EDDM