DNA-BINDING ACTIVITY OF VESICLES PRODUCED BY COMPETENCE DEFICIENT MUTANTS OF HEMOPHILUS

Membrane vesicles 40-70NM in diameter have been observed in the supernatant of cultures of a mutant strain of Haemophilus parainfluenzae (C-10) defective in transformation. Electron microscopy of thin sections of H. parainfluenzae (C-10) demonstrate that the vesicles are produced by budding off the outer membrane. Vesicles purified by differential centrifugation possess a DNase resistant DNA binding activity, and the membrane-DNA complex has been analyzed on CsCl gradients and shown to band at a density of 1.35g/cc. Mutants of H. influenzae having similiar properties have also been isolated. We report the method of isolation and some of the biochemical properties of vesicles from H. parainfluenzae and H. influenzae. © 1979.