Conserved translational frameshift in dsDNA bacteriophage tail assembly genes

Area of Science:

• Molecular Biology
• Virology
• Bioinformatics

Background:

• Programmed translational frameshifting is a mechanism observed in various genetic elements, including retroviruses and bacterial insertion sequences.
• In bacteriophage lambda, a -1 frameshift regulates the synthesis of overlapping proteins (gpG and gpGT) vital for tail assembly.

Purpose of the Study:

• To investigate the conservation and prevalence of programmed translational frameshifting in double-stranded DNA (dsDNA) phage tail assembly genes.
• To identify and experimentally validate novel frameshifting sites in diverse phage genomes.

Main Methods:

• Development of bioinformatic tools to predict -1 frameshifting sites.
• Experimental confirmation of predicted frameshifting sites in five additional bacteriophages.
• Identification of a -2 frameshift in phage Mu.

Main Results:

• Programmed translational frameshifting is a conserved mechanism in the tail assembly genes of dsDNA phages, independent of sequence similarity.
• Frameshifting sites were identified in most phages with contractile or noncontractile tails regulated by tape measure proteins.
• Evidence for both -1 and -2 frameshifts was found across a wide range of phages infecting Eubacteria and Archaea.

Conclusions:

• The conserved frameshift mechanism suggests a common, ancient ancestry for the tail genes of dsDNA phages.
• This frameshifting is a fundamental component of tail assembly across a broad spectrum of dsDNA phages.
• The findings highlight the evolutionary significance of translational control in phage biology.