Functional characterization of the Shigella dysenteriae heme ABC transporter.
The heme ATP binding cassette (ABC) transporter, ShuUV, of Shigella dysenteriae has been incorporated into proteoliposomes. Functional characterization of ShuUV revealed that ATP hydrolysis and transport of heme from the periplasmic binding protein, ShuT, to the cytoplasmic binding protein, ShuS, are coupled. Site-directed mutagenesis of ShuT residues proposed to be required for stabilization of the complex abolished heme transport. Furthermore, residues His-252 and His-262, located in the translocation channel of ShuU, were required for the release of heme from ShuT and translocation to ShuS. The initial functional characterization of an in vitro heme uptake system provides a platform for future spectroscopic studies.
Burkhard
Kimberly A
KA
Department of Pharmaceutical Sciences, School of Pharmacy, 20 Penn Street, University of Maryland, Baltimore, Maryland 21201-1140, USA.
Wilks
Angela
A
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001692:Biological Transport / Q000502:physiology; D006418:Heme / Q000378:metabolism*; D006639:Histidine / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012762:Shigella dysenteriae / Q000235:genetics / Q000378:metabolism*
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D006418:Heme; D006639:Histidine; D000255:Adenosine Triphosphate