Reexamination of phenotypic defects in rec-1 and rec-2 mutants of Haemophilus influenzae Rd

J Bacteriol. 1985 Aug;163(2):629-34. doi: 10.1128/jb.163.2.629-634.1985.

Abstract

Radiolabeled donor DNA is efficiently taken up into competent H. influenzae Rd rec-2 mutant cells but does not undergo the rapid degradation observed in wild-type cells. Furthermore, donor label is not recovered in the chromosome even after 1 h. The donor DNA appears to remain in a protected state in a compartment that can be separated from the rest of the cell. We interpret this as a failure of the donor DNA to be translocated out of the transformasome. In contrast, rec-1 cells translocate labeled donor DNA normally. The donor label accumulates in the recipient chromosome, but, as expected for cells with a recombination defect, there is no preferential localization of the label in sites homologous to the donor DNA. In addition, we have observed two enzymatic activities that act on transformasome-associated DNA of rec-2 cells, an endonuclease which may play a role in the translocation of closed circular DNA and a phosphatase.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Bacteriophages / genetics
  • Base Composition
  • Base Sequence
  • Biological Transport
  • DNA, Bacterial / metabolism*
  • Haemophilus influenzae / genetics*
  • Mutation*
  • Phenotype
  • Phosphorus Radioisotopes
  • Plasmids
  • Protein Biosynthesis
  • Transformation, Bacterial

Substances

  • DNA, Bacterial
  • Phosphorus Radioisotopes
  • Adenosine Triphosphate