RbsA is the cytoplasmic ATP-binding cassette subunit of the high-affinity RbsABC D-ribose importer of Escherichia coli. Its two fused nucleotide-binding domains hydrolyze ATP at the inner face of the cytoplasmic membrane to energize translocation of periplasmic RbsB-bound D-ribose through the RbsC2 permease dimer. RbsA associates with RbsC in an ADP-bound state and with RbsB and RbsC in the full RbsABC2 complex trapped with ATP, Mg2+ and vanadate. Mutants lacking RbsA lose high-affinity ribose transport but can grow on high ribose concentrations through a second, low-affinity uptake route.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005515 protein binding | IPI PMID:24561554 The binary protein-protein interaction landscape of Escheric... | REMOVE | Summary: Y2H interaction with PhnG from a binary interactome screen. Reason: Bare protein binding is uninformative under the project protein-binding policy. Removal does not dispute the reported interaction; the functional content is captured by the RbsABC complex and transporter-activity annotations. |
| GO:0005515 protein binding | IPI PMID:25533465 In vitro reassembly of the ribose ATP-binding cassette trans... | REMOVE | Summary: Co-purification of RbsA with RbsC in the reconstituted ribose transporter. Reason: Bare protein binding is uninformative under the project protein-binding policy. Removal does not dispute the reported interaction; the functional content is captured by the RbsABC complex and transporter-activity annotations. Supporting Evidence: PMID:25533465 The ribose transporter in Escherichia coli is a tripartite complex consisting of a cytoplasmic ATP-binding cassette protein, RbsA, with fused nucleotide binding domains; a transmembrane domain homodimer, RbsC2; and a periplasmic substrate binding protein, RbsB. |
| GO:0005524 ATP binding | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: InterPro ABC-transporter ATP-binding domain mapping to ATP binding. Reason: ATP binding is true (two Walker A motifs) but is a prerequisite of the core ATP hydrolysis activity rather than the function itself; kept as non-core, consistent with sibling ABC ATPase reviews. Supporting Evidence: file:ECOLI/rbsA/rbsA-uniprot.txt DR Pfam; PF00005; ABC_tran; 2. |
| GO:0005524 ATP binding | ISM PMID:3086314 An analysis of the structure of the product of the rbsA gene... | KEEP AS NON CORE | Summary: Sequence analysis identifying Walker-type ATP-binding motifs in RbsA. Reason: Correct sequence-based inference of nucleotide binding; non-core relative to ATP hydrolysis-coupled transport. Supporting Evidence: PMID:3086314 Each gene product contains a sequence of glycine and basic residues which are characteristic of an ATP-binding site |
| GO:0005524 ATP binding | ISM PMID:9593292 The Escherichia coli ATP-binding cassette (ABC) proteins. | KEEP AS NON CORE | Summary: Genome-wide survey of E. coli ABC proteins, classifying RbsA as an ABC domain protein. Reason: Same claim as the other ATP binding rows, from a review-level genome survey; consistent non-core action. Supporting Evidence: PMID:9593292 The ABC domains are often, but not exclusively, the energy-generating domains of multicomponent membrane-bound transporters. |
| GO:0005886 plasma membrane | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT propagation of plasma membrane activity location across carbohydrate ABC ATPases. Reason: RbsA acts as a peripheral subunit on the cytoplasmic face of the inner (plasma) membrane, docked on RbsC; the node includes RbsA itself and other experimentally studied E. coli carbohydrate ABC ATPases, and the location is where the transport activity occurs. Supporting Evidence: file:ECOLI/rbsA/rbsA-uniprot.txt CC -!- SUBCELLULAR LOCATION: Cell inner membrane {ECO:0000255|HAMAP- PMID:25533465 The ribose transporter in Escherichia coli is a tripartite complex consisting of a cytoplasmic ATP-binding cassette protein, RbsA, with fused nucleotide binding domains; a transmembrane domain homodimer, RbsC2; and a periplasmic substrate binding protein, RbsB. |
| GO:0005886 plasma membrane | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt subcellular location mapping to plasma membrane. Reason: Consistent with the IBA row and the RbsABC2 complex architecture. Supporting Evidence: file:ECOLI/rbsA/rbsA-uniprot.txt CC -!- SUBCELLULAR LOCATION: Cell inner membrane {ECO:0000255|HAMAP- |
| GO:0015147 L-arabinose transmembrane transporter activity | IBA GO_REF:0000033 | MARK AS OVER ANNOTATED | Summary: PAINT propagation of L-arabinose transporter activity from a node seeded by AraG. Reason: The only experimental source in WITH/FROM is AraG (P0AAF3), the ATPase of the L-arabinose importer. RbsA sits in the ribose-importer clade (HAMAP MF_01716, NCBIfam rbsA) and all transport evidence for RbsABC concerns D-ribose; no study shows L-arabinose import by RbsABC. The arabinose specificity is a property of the AraFGH system that does not transfer across the substrate-diversified family. Propagation Review Root cause: PROPAGATION BAD Failure modes: FUNCTIONAL DIVERGENCE Sources checked: PANTHER:PTN001953353 · PANTHER:PTN001953353 SUPPORTS SOURCE BUT NOT TARGET Ancestral node carrying L-arabinose transporter activity; its only listed experimental descendant is AraG. UniProtKB:P0AAF3 · AraG SUPPORTS SOURCE BUT NOT TARGET AraG is the ATPase of the L-arabinose AraFGH importer; its substrate does not transfer to the ribose-importer RbsA clade. Supporting Evidence: file:ECOLI/rbsA/rbsA-uniprot.txt DR NCBIfam; NF008030; rbsA; 1. PMID:6327617 It appears that the high-affinity transport system for ribose consists of the three components, ribose-binding protein, the 50-kilodalton RbsA protein, and the 27-kilodalton RbsC protein |
| GO:0015407 ABC-type monosaccharide transporter activity | IDA PMID:25533465 In vitro reassembly of the ribose ATP-binding cassette trans... | MODIFY | Summary: Reconstituted RbsABC complex as an ABC-type monosaccharide importer. Reason: Correct but general; the substrate is D-ribose, so the specific child GO:0015611, which this gene already carries, is preferred (contributes_to for the ATPase subunit). Proposed replacements: ABC-type D-ribose transporter activity Supporting Evidence: PMID:25533465 The ribose transporter in Escherichia coli is a tripartite complex consisting of a cytoplasmic ATP-binding cassette protein, RbsA, with fused nucleotide binding domains; a transmembrane domain homodimer, RbsC2; and a periplasmic substrate binding protein, RbsB. |
| GO:0015591 D-ribose transmembrane transporter activity | IDA PMID:6327617 Molecular cloning and characterization of genes required for... | MODIFY | Summary: Genetic and minicell definition of rbsA as required for high-affinity ribose transport. Reason: D-ribose transmembrane transporter activity is correct but less specific than the ABC-type D-ribose transporter activity (GO:0015611) the gene already carries; RbsA contributes the ATPase to that activity. Proposed replacements: ABC-type D-ribose transporter activity Supporting Evidence: PMID:6327617 It appears that the high-affinity transport system for ribose consists of the three components, ribose-binding protein, the 50-kilodalton RbsA protein, and the 27-kilodalton RbsC protein |
| GO:0015611 ABC-type D-ribose transporter activity | IEA GO_REF:0000120 | ACCEPT | Summary: UniRule/Rhea mapping of ABC-type D-ribose transporter activity (RHEA:29903, EC 7.5.2.7). Reason: Core function: RbsA energizes the RbsABC D-ribose importer. Strictly, the subunit contributes to this complex activity. Supporting Evidence: file:ECOLI/rbsA/rbsA-uniprot.txt CC -!- FUNCTION: Part of the ABC transporter complex RbsABC involved in ribose PMID:25533465 The ribose transporter in Escherichia coli is a tripartite complex consisting of a cytoplasmic ATP-binding cassette protein, RbsA, with fused nucleotide binding domains; a transmembrane domain homodimer, RbsC2; and a periplasmic substrate binding protein, RbsB. |
| GO:0015749 monosaccharide transmembrane transport | IEA GO_REF:0000117 | MODIFY | Summary: ARBA rule assigning monosaccharide transmembrane transport. Reason: Correct but general; the experimentally supported process is D-ribose transmembrane transport (GO:0015752), already on this gene. Proposed replacements: D-ribose transmembrane transport Supporting Evidence: PMID:6327617 It appears that the high-affinity transport system for ribose consists of the three components, ribose-binding protein, the 50-kilodalton RbsA protein, and the 27-kilodalton RbsC protein |
| GO:0015751 arabinose transmembrane transport | IEA GO_REF:0000108 | MARK AS OVER ANNOTATED | Summary: Inter-ontology link from the L-arabinose transporter activity IBA. Reason: Derived mechanically from the over-propagated L-arabinose transporter activity IBA; there is no evidence that RbsABC imports arabinose. Supporting Evidence: PMID:6327617 It appears that the high-affinity transport system for ribose consists of the three components, ribose-binding protein, the 50-kilodalton RbsA protein, and the 27-kilodalton RbsC protein |
| GO:0015752 D-ribose transmembrane transport | IDA PMID:25533465 In vitro reassembly of the ribose ATP-binding cassette trans... | ACCEPT | Summary: In vitro reassembly of RbsABC2 supporting a role in ribose transport. Reason: Core process of the RbsA ATPase subunit. Supporting Evidence: PMID:25533465 The ribose transporter in Escherichia coli is a tripartite complex consisting of a cytoplasmic ATP-binding cassette protein, RbsA, with fused nucleotide binding domains; a transmembrane domain homodimer, RbsC2; and a periplasmic substrate binding protein, RbsB. PMID:25533465 We were able to purify a full complex, RbsABC2, in the presence of stable, transition state mimics (ATP, Mg(2+), and VO4) |
| GO:0015752 D-ribose transmembrane transport | IMP PMID:6327617 Molecular cloning and characterization of genes required for... | ACCEPT | Summary: rbsA mutants defective in high-affinity ribose transport. Reason: Genetic evidence for the core process. Supporting Evidence: PMID:6327617 that were specifically defective in utilization or in high-affinity transport of D-ribose PMID:6327617 It appears that the high-affinity transport system for ribose consists of the three components, ribose-binding protein, the 50-kilodalton RbsA protein, and the 27-kilodalton RbsC protein |
| GO:0016020 membrane | IDA PMID:25533465 In vitro reassembly of the ribose ATP-binding cassette trans... | MODIFY | Summary: Membrane association of RbsA in the reconstituted transporter. Reason: Correct but general; RbsA is a peripheral subunit of the inner (plasma) membrane complex, and the gene already carries GO:0005886. Proposed replacements: plasma membrane Supporting Evidence: PMID:25533465 The ribose transporter in Escherichia coli is a tripartite complex consisting of a cytoplasmic ATP-binding cassette protein, RbsA, with fused nucleotide binding domains; a transmembrane domain homodimer, RbsC2; and a periplasmic substrate binding protein, RbsB. |
| GO:0016887 ATP hydrolysis activity | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro ABC transporter domain mapping to ATP hydrolysis activity. Reason: Core catalytic activity of the energy-coupling subunit; the UniProt record reports kinetic parameters for ATP. Supporting Evidence: file:ECOLI/rbsA/rbsA-uniprot.txt CC -!- FUNCTION: Part of the ABC transporter complex RbsABC involved in ribose file:ECOLI/rbsA/rbsA-uniprot.txt CC KM=140 uM for ATP {ECO:0000269|PubMed:8762140}; |
| GO:0043190 ATP-binding cassette (ABC) transporter complex | IDA PMID:25533465 In vitro reassembly of the ribose ATP-binding cassette trans... | MODIFY | Summary: Purification of the RbsAC and RbsABC2 complexes. Reason: Correct but general; the reconstituted complex contains the substrate-binding protein RbsB, so the specific child GO:0055052, already on this gene by IPI, is preferred. Proposed replacements: ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing Supporting Evidence: PMID:25533465 We were able to purify a full complex, RbsABC2, in the presence of stable, transition state mimics (ATP, Mg(2+), and VO4) |
| GO:0055052 ATP-binding cassette (ABC) transporter complex, substrate-binding subunit-containing | IPI PMID:25533465 In vitro reassembly of the ribose ATP-binding cassette trans... | ACCEPT | Summary: RbsA in the full RbsABC2 complex including the substrate-binding protein RbsB. Reason: Directly supported by complex purification. Supporting Evidence: PMID:25533465 We were able to purify a full complex, RbsABC2, in the presence of stable, transition state mimics (ATP, Mg(2+), and VO4) PMID:25533465 The ribose transporter in Escherichia coli is a tripartite complex consisting of a cytoplasmic ATP-binding cassette protein, RbsA, with fused nucleotide binding domains; a transmembrane domain homodimer, RbsC2; and a periplasmic substrate binding protein, RbsB. |
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