Genetic approaches to cell biology and metabolism of spirochetes.

Genetic analysis and methodology have only comparatively recently been applied to the study of spirochetes. Although genetic transfer procedures for spirochetes are not widely available, there are several examples of progress in genetic analysis of spirochetes by other approaches. Some examples of these approaches are the following. 1) Genes for synthetic pathways in Treponema and Leptospira have been cloned by complementation of Escherichia coli serving as plasmid hosts. 2) The OspA protein of Borrelia burgdorferi has been overexpressed in E. coli without the signal peptide; the recombinant product has been suitable for circular dichroism as well as other biochemical analyses. 3) The heat shock proteins of B. burgdorferi are homologous to heat shock proteins of E. coli. 4) Enzyme activity profiles of B. burgdorferi and other spirochetes show strain heterogeneity and also indicate which biosynthetic and enzymatic activities are conserved within different spirochetes. 5) The gene organization of rRNA genes have revealed differences between spirochetes and other types of bacteria.