User:Lori Wetmore/Sandbox 4
From Proteopedia
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<scene name='User:Lori_Wetmore/Sandbox_4/Sav1866/4'>TextToBeDisplayed</scene> | <scene name='User:Lori_Wetmore/Sandbox_4/Sav1866/4'>TextToBeDisplayed</scene> | ||
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=='''General ABC Structure'''== | =='''General ABC Structure'''== | ||
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| + | The ATP binding cassette is the most conserved part of an ABC transporter. All ABCs consist of two domains: a RecA-like domain, containing both the Walker A and Walker B motifs, and a helical domain, that contains a unique LSGGQ motif. The two domains are joined by flexible loops, one of which, the Q loop, mediates the interaction between the ABC and the TMD. | ||
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| + | ABC transporters function only when assembled into homodimers. The <scene name='User:Lori_Wetmore/Sandbox_4/Sav1866/6'>two ATP binding sites</scene> of an assembled transporter are at the interfaces of two ABC subunits, where the ATP interacts with the Walker A motif on one subunit and the LSGGQ motif on the other. | ||
Revision as of 02:40, 27 September 2010
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| 2hyd, resolution 3.00Å () | |||||||||
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| Ligands: | , | ||||||||
| Gene: | SAV1866 (Staphylococcus aureus) | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Contents |
Background Information
ATP-binding cassette (ABC) transporters are a superfamily of integral membrane proteins that harness the energy of ATP binding and hydrolysis to drive the trans-membrane movement of a variety of small molecules. ABC transporters function as homodimers, in which ATP binding and hydrolysis occurs in two sites that the interface of the nucleotide binding domains (NBD), while the paired transmembrane domains (TMD) facilitate substrate transport. Substrates may be imported or exported, depending upon the structure of the transporter. In ABC importers, which have only been found in prokaryotes, the NBD and TMD are separate polypeptides; however, in the ubiquitous exporters, the NBD and TMD are fused.
ABC transporters are of particular medical interest, as they may contribute to the pathogenicity and drug resistance of pathogenic bacteria and some cancers.[1]
General ABC Structure
The ATP binding cassette is the most conserved part of an ABC transporter. All ABCs consist of two domains: a RecA-like domain, containing both the Walker A and Walker B motifs, and a helical domain, that contains a unique LSGGQ motif. The two domains are joined by flexible loops, one of which, the Q loop, mediates the interaction between the ABC and the TMD.
ABC transporters function only when assembled into homodimers. The of an assembled transporter are at the interfaces of two ABC subunits, where the ATP interacts with the Walker A motif on one subunit and the LSGGQ motif on the other.
ABC Exporters
Type I ABC Importers
Type II ABC Importers
References
- ↑ Davidson AL, Dassa E, Orelle C, Chen J. Structure, function, and evolution of bacterial ATP-binding cassette systems. Microbiol Mol Biol Rev. 2008 Jun;72(2):317-64, table of contents. PMID:18535149 doi:10.1128/MMBR.00031-07
