Secreted euryarchaeal microhalocins kill hyperthermophilic crenarchaea

C. Haseltine, T. Hill, R. Montalvo-Rodriguez, S. K. Kemper, R. F. Shand, P. Blum

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Few antibiotics targeting members of the archaeal domain are currently available for genetic studies. Since bacterial antibiotics are frequently directed against competing and related organisms, archaea by analogy might produce effective antiarchaeal antibiotics. Peptide antibiotic (halocin) preparations from euryarchaeal halophilic strains S8a, GN101, and TuA4 were found to be toxic for members of the hyperthermophilic crenarchaeal genus Sulfolobus. No toxicity was evident against representative bacteria or eukarya. Halocin S8 (strain S8a) and halocin R1 (strain GN101) preparations were cytostatic, while halocin A4 (strain TuA4) preparations were cytocidal. Subsequent studies focused on the use of halocin A4 preparations and Sulfolobus solfataricus. Strain TuA4 cell lysates were not toxic for S. solfataricus, and protease (but not nuclease) treatment of the halocin A4 preparation inactivated toxicity, indicating that the A4 toxic factor must be a secreted protein. Potassium chloride supplementation of the Sulfolobus assay medium potentiated toxicity, implicating use of a salt-dependent mechanism. The utility of halocin A4 preparations for genetic manipulation of S. solfataricus was assessed through the isolation of UV-induced resistant mutants. The mutants exhibited stable phenotypes and were placed into distinct classes based on their levels of resistance.

Original languageEnglish (US)
Pages (from-to)287-291
Number of pages5
JournalJournal of bacteriology
Issue number1
StatePublished - 2001

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology


Dive into the research topics of 'Secreted euryarchaeal microhalocins kill hyperthermophilic crenarchaea'. Together they form a unique fingerprint.

Cite this