Team:Aix-Marseille/M13

M13 phage

Life cycle

M13 phage life cycle in Escherichia coli.

The M13 life cycle begins with passage of the phage genome into a host cell in a process induced by protein III (pIII). First, the single-strand DNA (ssDNA) is converted in double-strand DNA (dsDNA) by pII and pX, which allow the production of phage's protein.

After a while, as the concentrations of phage proteins increase and the ssDNA is back converted as dsDNA. The protein V (pV) binds to the ssDNA genomes for packaging into progeny phages. It recognise the single stranded M13 origin of replication. The pV-sequestered ssDNA is recognized by the membrane spanning phage assembly complex. [1]

Protein III (p3)

Description of the domains composing M13's protein III.

The molecular interactions that mediate the entry of Escherichia coli derived filamentous phages into their hosts have been studied in considerable detail. The 424-amino-acid protein III is thought to consist of a leader sequence and three domains, separated by glycine-rich regions, that serve distinct roles in phage entry and release. The first two pIII domains, D1 and D2, are required for M13 adsorption and entry, while the third domain D3 is required for the assembly and release of M13 particles from host.[2]

References

  1. ↑ Smeal, S. W., Schmitt, M. A., Pereira, R. R., Prasad, A. & Fisk, J. D. Simulation of the M13 life cycle I: Assembly of a genetically-structured deterministic chemical kinetic simulation. Virology 500, 259–274 (2017).
  2. ↑ Heilpern, A. J. & Waldor, M. K. pIIICTX, a predicted CTXphi minor coat protein, can expand the host range of coliphage fd to include Vibrio cholerae. J. Bacteriol. 185, 1037–1044 (2003).