DNA-uptake machinery of naturally competent Vibrio cholerae

Transformation allows naturally competent bacteria to take up DNA from the environment and integrate the DNA into the chromosome by recombination. In Gram-negative bacteria, the DNA-uptake machinery shuttles the incoming DNA across the outer membrane, the periplasmic space, and the inner membrane. This study investigates the DNA-uptake complex of the human pathogen Vibrio cholerae, using a cellular biology-based approach. We visualized different components of this multicomponent complex, including a type IV pilus appendage, determined their (co)localization within the bacterial cell, and conducted an analysis of competence-gene mutants. We conclude that the uptake of DNA occurs via (at least) a two-step process.