ABC transporter: Difference between revisions

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Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Zina Saadi, Alexander Berchansky, Michal Harel, Joel L. Sussman

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 == Function ==
-ABC Transporters has two main functionality acting either as exporters or importers. '''ABC ''Exporters''''' release bound drugs to the extracellular environment, while '''ABC ''Importers''''' accept substrate molecules from their relevant substrate-binding proteins<ref name="biochembook"/>. For instance the Vitamin B12 transporter BtuCD (PDB [[1l7v]]) is a binding protein-dependent ABC transporter system that uses the power of ATP hydrolysis to pump vitamin B12 into the cytoplasm of E. coli<ref name="BtuCD-Ecoli"/>.
+ABC Transporters have two main functionalities acting either as exporters or importers. '''ABC ''Exporters''''' release bound drugs to the extracellular environment, while '''ABC ''Importers''''' accept substrate molecules from their relevant substrate-binding proteins<ref name="biochembook"/>. For instance the Vitamin B12 transporter BtuCD (PDB [[1l7v]]) is a binding protein-dependent ABC transporter system that uses the power of ATP hydrolysis to pump vitamin B12 into the cytoplasm of E. coli<ref name="BtuCD-Ecoli"/>.
-'''ABC Exporters''' Use ATP to drive import and export functions providing multidrug resistance. In eukaryoles, for instance, ABC Transporters are problematic because they export therapeutic drugs such as those used in chemotherapy regimens, which must be changed frequently to avoid the rejection of the drugs<ref name="biochembook"/>.
+'''ABC Exporters''' use ATP to drive import and export functions providing multidrug resistance. In eukaryoles, for instance, ABC Transporters are problematic because they export therapeutic drugs such as those used in chemotherapy regimens, which must be changed frequently to avoid the rejection of the drugs<ref name="biochembook"/>.
+== Structural highlights ==
 To achieve export, ABC transporters require a minimum of four domains. Two transmembrane domains (TMDs) form the ligand binding sites and provide specificity, and two NBDs bind and hydrolyze ATP to drive the trans-location of the bound ligand. The NBDs, but not the TMDs, are homologous throughout the family and have several characteristic motifs including the Walker A and B motifs common to many nucleotide binding proteins and others like the ABC signature, stacking aromatic D, H, and Q loops, which are unique to the family<ref name="FourDomainsABCT"/>.