Open AccessDNA-binding vesicles released from the surface of a competence-deficient mutant of Haemophilus influenzae
Author(s) -
Michael F. Concino,
Sol H. Goodgal
Publication year - 1982
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.152.1.441-450.1982
Subject(s) - biology , dna , mutant , haemophilus influenzae , extracellular , cell membrane , bacterial outer membrane , biochemistry , microbiology and biotechnology , cell , escherichia coli , gene , antibiotics
Haemophilus influenzae com-51, a mutant deficient in DNA uptake, produces an extracellular DNA-binding activity. The activity was specific for Haemophilus DNA and was isolated from cell-free competence medium after incubation for 100 to 130 min. Initial steps in the purification procedure resulted in the loss of detectable binding activity, but activity was restored by the addition of a nonionic detergent. The active fractions contained vesicles derived from the outer membrane of the cells. The vesicles were produced only under conditions that normally lead to competence development. The lack of competence of com-51 cells was not due to loss of protein synthesis in M-IV competence medium or to competition of extracellular protein for exogenous DNA. Results suggest that the inability of cells to bind DNA was due in part to the loss of DNA receptors that are released into the medium in membrane fragments.