Caractérisation de 2 transporteurs ABC (“ATP-Binding Cassette”) bactériens de fonction inconnue : YheI/YheH de Bacillus subtilis et Rv1747 de Mycobacterium tuberculosis

Abstract : The multidrug resistance (MDR) phenotype of cancer cells is mostly associated with overexpression of membrane proteins which belong to the large superfamily of ABC (« ATP binding cassette ») transporters. These proteins couple ATP hydrolysis to the efflux of chemotherapeutic drugs. Homologous transporters from bacteria have been involved in antibiotic resistance.
Two new bacterial ABC transporters, Rv1747 from Mycobacterium tuberculosis and YheI/YheH from Bacillus subtilis, putatively involved in antibiotic resistance, have been studied here after heterologous expression in Escherichia coli and isolation of inverted membrane vesicles. This system has proved not to be useful for the study of Rv1747, due probably to codon usage differences between E. coli and M. tuberculosis. By contrast, we reached a high expression level of YheI/YheH which allowed the characterization of its transport and ATP hydrolysis activities. We thus showed that these two proteins associate to form a heterodimeric transporter able to efflux several structurally unrelated drugs, and that the two subunits play different roles in the catalytic mechanism. Finally, we managed to purify YheI/YheH in high yield, in a functional and stable state, which allowed us to extend its biochemical characterization and to obtain 2D crystals for structural studies by electron microscopy.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00369447
Contributor : Carmen Galian Barrueco <>
Submitted on : Thursday, March 19, 2009 - 7:01:40 PM
Last modification on : Friday, April 5, 2019 - 1:01:43 AM
Long-term archiving on: Tuesday, June 8, 2010 - 9:41:37 PM

Identifiers

  • HAL Id : tel-00369447, version 1

Collections

Citation

Carmen Galian Barrueco. Caractérisation de 2 transporteurs ABC (“ATP-Binding Cassette”) bactériens de fonction inconnue : YheI/YheH de Bacillus subtilis et Rv1747 de Mycobacterium tuberculosis. Biochimie [q-bio.BM]. Université Joseph-Fourier - Grenoble I, 2008. Français. ⟨tel-00369447⟩

Share

Metrics

Record views

484

Files downloads

4692