Analysis of the Topology of an F Plasmid Protein - Construction of TraQ::PhoA fusions
Abstract
F pilus filaments extend from the surface of bacteria carrying plasmid F and initiate intercellular contacts that allow conjugative DNA transfer to other cells. Secretion of the subunits in this filament depends on a small 94 amino acid inner membreane protein, TraQ. The membrane topology of TraQ was investigated by analysis of traQ::phoA fusion products. A plasmid containing both sequences was constructed and fusions were generated by in vitro deletion with Bal-31 and religation. Plasmids in transformants were screened for expression of alkaline phosphatase activity and by restriction enzyme analysis; expression of ³⁵S-methionine labeled proteins was also examined. The DNA sequence of plasmids that expressed a traQ::phoA fusion was then obtained. The results indicate that the N-terminal region of TraQ spans the bacterial membrane, and the C-terminal portion of the protein extends into the periplasm.
Description
Program year: 1996/1997Digitized from print original stored in HDR
Citation
Ward, Catherine H. (1994). Analysis of the Topology of an F Plasmid Protein - Construction of TraQ::PhoA fusions. University Undergraduate Fellow. Available electronically from https : / /hdl .handle .net /1969 .1 /CAPSTONE -WardC _1994.