Biology subjects

Billau, F. A.

Publications and source records attributed to Billau, F. A..

2 recordsLinked to original sources

bioRxiv2024

Temporal epigenome modulation enables efficient bacteriophage engineering and functional analysis of phage DNA modifications

Lytic bacteriophages hold substantial promise in medical and biotechnological applications. CRISPR-Cas systems offer a way to explore these mechanisms via site-specific phage mutagenesis. However, phages can resist Cas-mediated cleavage through extensive DNA modifications like cytosine glycosylation, hindering mutagenesis efficiency. Our study utilizes the eukaryotic enzyme NgTET to temporarily reduce phage DNA modifications, facilitating Cas nuclease cleavage and enhancing mutagenesis efficiency. This approach enables precise DNA targeting and seamless point mutation integration, exemplified by deactivating specific ADP-ribosyltransferases crucial for phage infection. Furthermore, by temporally removing DNA modifications, we elucidated the effects of these modifications on T4 phage infections without necessitating gene deletions. Our results present a strategy enabling the investigation of phage epigenome functions and streamlining the engineering of phages with cytosine DNA modifications. The described temporal modulation of the phage epigenome is valuable for synthetic biology and fundamental research to comprehend phage infection mechanisms through the generation of mutants.

microbiology↗

bioRxiv2021

Viral ADP-ribosyltransferases attach RNA chains to host proteins

The mechanisms by which viruses hijack their hosts genetic machinery are of current interest. When bacteriophage T4 infects Escherichia coli, three different ARTs (ADP-ribosyltransferases) reprogram the hosts transcriptional and translational apparatus through ADP-ribosylation using nicotinamide adenine dinucleotide (NAD) as substrate 1,2. Recently, NAD was identified as a 5-modification of cellular RNAs 3-5. Here, we report that T4 ART ModB accepts not only NAD but also NAD-capped RNA (NAD-RNA) as substrate and attaches entire RNA chains to acceptor proteins in an "RNAylation" reaction. ModB specifically RNAylates ribosomal proteins rS1 and rL2 at defined arginine residues, and a specific group of E. coli and T4 phage RNAs is linked to rS1 in vivo. T4 phages that express an inactive mutant of ModB show a decreased burst size and slowed lysis of E. coli. Our findings reveal a distinct biological role of NAD-RNA, namely activation of the RNA for enzymatic transfer to proteins. The attachment of specific RNAs to ribosomal proteins might provide a strategy for the phage to modulate the hosts translation machinery. This work exemplifies the first direct connection between RNA modification and post-translational protein modification. As ARTs play important roles far beyond viral infections 6, RNAylation may have far-reaching implications.

microbiology↗