Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
TreeGrafter-generated GO annotations
Combined Automated Annotation using Multiple IEA Methods
UniProtKB record A0A0H2MHH3 (A0A0H2MHH3_VARPD) - Biopolymer transport protein ExbB from Variovorax paradoxus TBEA6
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VPARA_25810 (exbB4, A0A0H2MHH3) is a 238-aa inner-membrane protein with three transmembrane helices (residues 20-41, 127-150, and 174-195) and a MotA/TolQ/ExbB proton-channel domain (Pfam PF01618, residues 100-201), belonging to PANTHER subfamily PTHR30625:SF14 (BIOPOLYMER TRANSPORT PROTEIN EXBB).
"FT DOMAIN 100..201
FT /note="MotA/TolQ/ExbB proton channel"
FT /evidence="ECO:0000259|Pfam:PF01618""
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VPARA_25810 (exbB4) corresponds to EMBL CDS accession KLN56275.1 on genomic contig JZWI01000012, where consecutive CDS accessions (KLN56274.1-KLN56277.1) and locus tags stepping by 10 place exbB4 between exbD5 (VPARA_25800, KLN56274.1) and tonB (VPARA_25820, KLN56276.1).
"DR EMBL; JZWI01000012; KLN56275.1; -; Genomic_DNA."
TonB-dependent transporters: regulation, structure, and function.
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Outer-membrane TonB-dependent siderophore transporters require the inner-membrane TonB-ExbB-ExbD complex to harvest the proton-motive force across the cytoplasmic membrane and transduce energy to the outer membrane.
"These transporters show high affinity and specificity for metal chelates called siderophores and require energy derived from the protonmotive force across the inner membrane to transport them (33, 87). To tap this energy source, TBDTs must interact with an inner membrane protein complex consisting of TonB, ExbB, and ExbD (72)."
Energization of Outer Membrane Transport by the ExbB ExbD Molecular Motor.
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ExbB forms a pentameric inner-membrane pore enclosing an ExbD dimer that harvests the cytoplasmic-membrane proton-motive force and transmits it to TonB to open outer-membrane TonB-dependent transporters.
"ExbB forms a pentamer with a pore inside, in which an ExbD dimer resides. This complex harvests the energy of the pmf and transmits it to TonB."