The multisite character of host-range mutations in bacteriophage λ

Jocelyn E. Shaw, Hermine Bingham, Clarence R. Fuerst, Mark L. Pearson

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Mapping of the h and hh* host-range mutations in phage λ by two-point crosses with reference J- point mutations, and with λgal deleted for part of J, locates these mutations in the promoter-distal portion of the J cistron. Analysis of phenotypic h+ recombinants, formed in crosses of the type h or hh* × Jt-, or h+ revertants of h, hh*, and Jdef mutants, indicates that such phenotypic h+ particles often retain cryptic h determinants. Similar determinants are also present in some common laboratory strains of λ. These h+ recombinants and revertants carry a variety of different h markers, since recombination analysis allows several classes of particles carrying cryptic h markers to be distinguished. These genetic data suggest that the extended host-range phenotype in λ is due to multiple rather than single, mutations in the distal region of gene J, although the number of sites involved and their arrangement remain uncertain. The genetic location of the h and hh* mutations is confirmed at the physical level by comparing the tryptic peptide maps of the J proteins purified from lysates of cells infected with different h+, h, hh*, Jam, and J434 phage and from purified λh+ virions. Examination of these peptide maps shows there are several methionine-containing peptides altered in the h and hh* maps. Some of these altered peptides are derived from the C-terminal 5-10% of the J polypeptide in the region of nonhomology between λ and 434.

Original languageEnglish (US)
Pages (from-to)180-194
Number of pages15
Issue number1
StatePublished - Nov 1977

Bibliographical note

Funding Information:
We are grateful to Maxime Schwartz and Maurice Hofnung, Pasteur Institute, Paris, for providing h and hh* phage strains and for communicating the results of their experiments prior to publication. This work has been supported by grants from the Medical Research Council of Canada.


Dive into the research topics of 'The multisite character of host-range mutations in bacteriophage λ'. Together they form a unique fingerprint.

Cite this