FIG. 1.

Structural and functional analysis of a V. cholerae ppk mutant. (Left panel) Southern hybridization analysis. DNA from strains C6709-1 (WT) and AJB37 (ppk) was digested with EcoRI, and the fragments were separated in a 0.8% agarose gel and transferred to a positively charged nylon membrane. The membrane was hybridized with DNA flanking the ppk gene labeled with digoxigenin. MW, molecular weight markers. (Right panel) Poly-P biosynthesis. Strains C6709-1 (wild type) and AJB37 (ppk) were grown in LB medium, and incorporation of ³²P into high-molecular-weight poly-P was determined by TLC as described in Materials and Methods.