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2.A.34.1.1
NhaB Na+:H+ antiporter of 513 aas and 11 or 12 TMSs.  NhaB is physiologically important when the level of NhaA activity is growth limiting, when nhaA is not sufficiently induced, and/or when NhaA is not activated (Pinner et al. 1993). The  stoichiometry of NhaB is 3H+/2Na+, different from that of NhaA (Pinner et al. 1994). It is required for intracellular pH regulation under alkaline conditions (Shimamoto et al. 1994). Mutations D146A/D404A in the Klebsiella pneumoniae ortholog changed the stoichiometry to a H+:Na+ ratio of < 1 (Patiño-Ruiz et al. 2019).

Accession Number:P0AFA7
Protein Name:Na(+)/H(+) antiporter 2 NhaB aka B1186
Length:513
Molecular Weight:56728.00
Species:Escherichia coli [83333]
Number of TMSs:12
Location1 / Topology2 / Orientation3: Cell inner membrane1 / Multi-pass membrane protein2
Substrate Na+

Cross database links:

Genevestigator: P0AFA7
EchoBASE: EB1365
EcoGene: EG11392
eggNOG: COG3067
HEGENOM: HBG296776
RefSeq: AP_001811.1    NP_415704.1   
Entrez Gene ID: 944822   
Pfam: PF06450   
BioCyc: EcoCyc:NHAB-MONOMER    ECOL168927:B1186-MONOMER   
KEGG: ecj:JW1175    eco:b1186   

Gene Ontology

GO:0016021 C:integral to membrane
GO:0044459 C:plasma membrane part
GO:0015081 F:sodium ion transmembrane transporter activity
GO:0015385 F:sodium:hydrogen antiporter activity
GO:0006883 P:cellular sodium ion homeostasis
GO:0051452 P:intracellular pH reduction
GO:0015992 P:proton transport
GO:0010226 P:response to lithium ion
GO:0006814 P:sodium ion transport

References (9)

[1] “Cloning, sequencing, and expression of the nhaB gene, encoding a Na+/H+ antiporter in Escherichia coli.”  Pinner E.et.al.   1317851
[2] “A 718-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 12.7-28.0 min region on the linkage map.”  Oshima T.et.al.   8905232
[3] “The complete genome sequence of Escherichia coli K-12.”  Blattner F.R.et.al.   9278503
[4] “Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110.”  Hayashi K.et.al.   16738553
[5] “Physiological role of nhaB, a specific Na+/H+ antiporter in Escherichia coli.”  Pinner E.et.al.   8093613
[6] “Lithium toxicity and Na+(Li+)/H+ antiporter in Escherichia coli.”  Inaba K.et.al.   8019504
[7] “The NhaB Na+/H+ antiporter is essential for intracellular pH regulation under alkaline conditions in Escherichia coli.”  Shimamoto T.et.al.   7822245
[8] “Kinetic properties of NhaB, a Na+/H+ antiporter from Escherichia coli.”  Pinner E.et.al.   7929345
[9] “Global topology analysis of the Escherichia coli inner membrane proteome.”  Daley D.O.et.al.   15919996

External Searches:

  • Search: DB with
  • BLAST ExPASy (Swiss Institute of Bioinformatics (SIB) BLAST)
  • CDD Search (Conserved Domain Database)
  • Search COGs (Clusters of Orthologous Groups of proteins)
  • 2° Structure (Network Protein Sequence Analysis)

Analyze:

Predict TMSs (Predict number of transmembrane segments)
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FASTA formatted sequence
1:	MEISWGRALW RNFLGQSPDW YKLALIIFLI VNPLIFLISP FVAGWLLVAE FIFTLAMALK 
61:	CYPLLPGGLL AIEAVFIGMT SAEHVREEVA ANLEVLLLLM FMVAGIYFMK QLLLFIFTRL 
121:	LLSIRSKMLL SLSFCVAAAF LSAFLDALTV VAVVISVAVG FYGIYHRVAS SRTEDTDLQD 
181:	DSHIDKHYKV VLEQFRGFLR SLMMHAGVGT ALGGVMTMVG EPQNLIIAKA AGWHFGDFFL 
241:	RMSPVTVPVL ICGLLTCLLV EKLRWFGYGE TLPEKVREVL QQFDDQSRHQ RTRQDKIRLI 
301:	VQAIIGVWLV TALALHLAEV GLIGLSVIIL ATSLTGVTDE HAIGKAFTES LPFTALLTVF 
361:	FSVVAVIIDQ QLFSPIIQFV LQASEHAQLS LFYIFNGLLS SISDNVFVGT IYINEAKAAM 
421:	ESGAITLKQY ELLAVAINTG TNLPSVATPN GQAAFLFLLT SALAPLIRLS YGRMVWMALP 
481:	YTLVLTLVGL LCVEFTLAPV TEWFMQMGWI ATL