TOWARDS A STRUCTURAL BIOLOGY OF BACTERIAL CONJUGATION

Horizontal DNA transfer among bacteria (conjugation) requires the form ation of secure intercellular contacts before DNA transfer can occur. The formation of such contacts among Gram-negative bacteria is mediate d by conjugative pill. Like other pill, conjugative pill are filaments extending from the surface of donor cells. They are composed, in so f ar as is known, entirely of conjugative pilin subunits. Here, we revie w the structure of F-pilin, the subunit of which F-pili are composed. We emphasize recent studies suggesting a specific domain organization for F-pilin and present a model of how these domains might be arranged in filament subunits.