2.A.53.3.14 Bicarbonate:Na+ symporter of 564 aas and 11 putative TMSs. Crystal structures of the transmembrane domain (BicA(TM)) and the cytoplasmic STAS domain (BicA(STAS)) of BicA were solved (Wang et al. 2019). BicA(TM) was captured in an inward-facing HCO3--bound conformation with a '7+7' fold monomer. HCO3- bound to a cytoplasm-facing hydrophilic pocket within the membrane. BicA(STAS) is a compact homodimer, required for the dimerization of BicA. The dimeric structure of BicA was further analysed using cryo-electron microscopy and physiological analysis of the full-length BicA, and may represent the physiological unit of SLC26-family transporters. Comparing the BicA(TM) structure with the outward-facing transmembrane domain structures of other bicarbonate transporters suggested an elevator transport mechanism that is applicable to the SLC26/4 family of sodium-dependent bicarbonate transporters (Wang et al. 2019).
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Accession Number: | BAM53892.1 |
Protein Name: | BAM53892.1 bicarbonate transporter [Synechocystis sp. PCC 6803] |
Length: | 565 |
Molecular Weight: | |
Species: | Synechocystis sp. PCC 6803 [1148] |
Number of TMSs: | 11 |
Substrate |
hydrogencarbonate |
---|
1: MQITNKIHFR NLQGDLFGGV TAAVIALPMA LAFGIASGAG ATAGLWGAVI VGFFAALFGG
61: TPTLISEPTG PMTVVQTAVI ASLVAADPDN GLAMAFTVVM MAGLFQIAFG LLKLGKYVTM
121: MPYTVISGFM SGIGIILVIL QLAPFLGQAS PKGGVIGTLQ ALPNLVSNVR PVETLLALMT
181: VGIIWFMPSR WKKFAPPQLV ALVLGTIISI TLFGDLDIRR IGEIQAGLPA LQLPVFQADQ
241: LQRMLIDAAV LGMLGCIDAL LTSVVADSLT RTEHNSNKEL VGQGIGNVMS GLFGGLGGAG
301: ATMGTVVNIQ SGGRTALSGL IRAMVLLVVI LGAAKLAATI PLAVLAGIAF KVGVDIIDWG
361: FLKRAHHVSI KGALIMYAVI VLTVLVDLIA AVGIGVFIAN ILTIDRMSAL QSKAVKSISD
421: ADDEILLSAN EKRWLDEGNG RVLLFQLSGP MIFGVAKAIA REHNAIQECA AIVFDLSDVP
481: HLGVTASLAL ENAIEEAAEK GRAVYIVGAT GQTKRRLEKL QVFRFVPESN CYDDRSEALK
541: DAVLALGPHE SEDSPSSSSV QTTY