Abstract
OxIT is the oxalate/formate exchange protein that represents the vectorial component of a proton-motive metabolic cycle in Oxalobacter formigenes. Here we report the cloning and sequencing of OxIT and describe its expression in Escherichia coli. The OxIT amino acid sequence specifies a polytopic hydrophobic protein of 418 residues with a mass of 44,128 daltons. Analysis of hydropathy and consideration of the distribution of charged residues suggests an OxIT secondary structure having 12 transmembrane segments, oriented so that the N and C termini face the cytoplasm. Expression of OxIT in E. coli coincides with appearance of a capacity to carry out the self-exchange of oxalate and the heterologous, electrogenic exchange of oxalate with formate. The unusually high velocity of OxIT-mediated transport is also preserved in E. coli. We conclude that the essential features of OxIT are retained on its expression in E. coli.
Original language | English (US) |
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Pages (from-to) | 6789-6793 |
Number of pages | 5 |
Journal | Journal of Biological Chemistry |
Volume | 271 |
Issue number | 12 |
DOIs | |
State | Published - Mar 22 1996 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology