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M Blight

Publications and source records attributed to M Blight.

5 recordsLinked to original sources
PubMed1992

Characterization of the hemolysin transporter, HlyB, using an epitope insertion.

The prokaryotic hlyB gene product is a member of a superfamily of ATP-binding transport proteins that include the eukaryotic multidrug-resistance P-glycoprotein, the yeast STE6, and the cystic fibrosis CFTR gene products (Juranka, P. F., Zastawny, R. L., and Ling, V. (1989) FASEB J. 3, 2583-2592). Previous genetic studies have indicated that HlyB is involved in the transport of the 107-kDa HlyA protein from Escherichia coli; however, the HlyB protein has not been purified for biochemical studies due to its low abundance. In this study, we have engineered a monoclonal antibody epitope into the C-terminal end of HlyB that did not destroy its function. This has allowed us to use immunological methods to identify and localize various molecular forms of the HlyB protein present in vivo.

Amino Acid Sequence↗
PubMed1991

Analysis of the membrane organization of an Escherichia coli protein translocator, HlyB, a member of a large family of prokaryote and eukaryote surface transport proteins.

Haemolysin B (HlyB) is essential for secretion of the 107 x 10(3) Mr haemolysin A protein from Escherichia coli and is a member of a family of highly conserved, apparently ATP-dependent surface proteins in many organisms. We have shown in this study that both HlyB and HlyD fractionate primarily with the cytoplasmic membrane of E. coli and are accessible to proteases after removal of the outer membrane. We have measured experimentally the topological organization of HlyB within the membrane by construction of fusions to beta-lactamase as a reporter. The predicted folding of HlyB, with a minimum of six transmembrane segments, does not always coincide with regions of highest average hydrophobicity. This suggests that HlyB may have a novel organization within the bilayer. From our data and comparative sequence analysis, we have been able to predict very similar topological models for the other members of the HlyB family.

Amino Acid Sequence↗
PubMedDate not supplied

Haemolysin secretion from E coli.

Haemolysin (HlyA) secretion from E coli is directed by a specific C-terminal targeting signal, located within the last 27-50 amino acids, with quite novel characteristics. The HlyA molecule is secreted directly to the medium without a periplasmic intermediate or detectable proteolytic processing. The C-terminal domain of HlyA can also be used to promote the secretion of several other E coli and mammalian proteins. HlyD and HlyB are essential for translocation of HlyA to the medium and we propose that these proteins form a transenvelope complex which initially binds the HlyA signal followed by transport of HlyA to the medium. HlyB is a member of a family of membrane proteins engaged in ATP dependent secretion mechanisms conserved in many organisms including man (P-glycoprotein and the CF protein). In this review we discuss the structure, function and regulation of the secretion mechanism.

Amino Acid Sequence↗