Genetic dissection of T4 lysis. Academic Article uri icon


  • t is the holin gene for coliphage T4, encoding a 218-amino-acid (aa) protein essential for the inner membrane hole formation that initiates lysis and terminates the phage infection cycle. T is predicted to be an integral membrane protein that adopts an N(in)-C(out) topology with a single transmembrane domain (TMD). This holin topology is different from those of the well-studied holins S105 (3 TMDs; N(out)-C(in)) of the coliphage lambda and S68 (2 TMDs; N(in)-C(in)) of the lambdoid phage 21. Here, we used random mutagenesis to construct a library of lysis-defective alleles of t to discern residues and domains important for holin function and for the inhibition of lysis by the T4 antiholin, RI. The results show that mutations in all 3 topological domains (N-terminal cytoplasmic, TMD, and C-terminal periplasmic) can abrogate holin function. Additionally, several lysis-defective alleles in the C-terminal domain are no longer competent in binding RI. Taken together, these results shed light on the roles of the previously uncharacterized N-terminal and C-terminal domains in lysis and its real-time regulation.

published proceedings

  • J Bacteriol

altmetric score

  • 3

author list (cited authors)

  • Moussa, S. H., Lawler, J. L., & Young, R. y.

citation count

  • 15

complete list of authors

  • Moussa, Samir H||Lawler, Jessica L||Young, Ry

publication date

  • June 2014