CrAss-like phages play an important role in maintaining ecological balance in the human intestinal microbiome. However, their genetic diversity and lifestyle are still insufficiently studied. In this study, a novel CrAssE-Sib phage genome belonging to the epsilon crAss-like phage genomes was found. Comparative analysis indicated that epsilon crAss-like phages are divided into two putative genera, which were proposed to be named and ; CrAssE-Sib belongs to the former. The crAssE-Sib genome contains a diversity-generating retroelement (DGR) cassette with all essential elements, including the reverse transcriptase (RT) and receptor binding protein (RBP) genes. However, this RT contains the GxxxSP motif in its fourth domain instead of the usual GxxxSQ motif found in all known phage and bacterial DGRs. RBP encoded by CrAssE-Sib and other has an unusual structure, and no similar phage proteins were found. In addition, crAssE-Sib and other encode conserved prophage repressor and anti-repressors that could be involved in lysogenic-to-lytic cycle switches. Notably, DNA primase sequences of epsilon crAss-like phages are not included in the monophyletic group formed by the DNA primases of all other crAss-like phages. Therefore, epsilon crAss-like phage substantially differ from other crAss-like phages, indicating the need to classify these phages into a separate family.
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http://dx.doi.org/10.3390/v16040513 | DOI Listing |
bioRxiv
November 2024
APC Microbiome Ireland & School of Microbiology, University College Cork, Cork, T12 YT20, Ireland.
Background: Bacteriophages (phages) and bacteria within the gut microbiome persist in long-term stable coexistence. These interactions are driven by eco-evolutionary dynamics, where bacteria employ a variety of mechanisms to evade phage infection, while phages rely on counterstrategies to overcome these defences. Among the most abundant phages in the gut are the crAss-like phages that infect members of the Bacteroidales, in particular In this study, we explored some of the mechanisms enabling the co-existence of four phage-Bacteroidales host pairs using a multi-omics approach (transcriptomics, proteomics and metabolomics).
View Article and Find Full Text PDFSci Total Environ
December 2024
Department of Genetics, Microbiology and Statistics, Section of Microbiology, Virology and Biotechnology, School of Biology, University of Barcelona, Diagonal 643, E-08028 Barcelona, Spain. Electronic address:
Due to their abundance in the human gut, human specificity, and global distribution, some crAss-like phages, including the original p-crAssphage, have been proposed as indicators of human fecal pollution suitable for microbial source tracking (MST). The prevalence of crAss-like phages in water, and consequently their usefulness as MST indicators, is determined by their ability to survive various inactivation and disinfection processes. Recently, we isolated new crAss-like phages (named crAssBcn phages) capable of infecting Bacteroides intestinalis and exhibiting a wide geographical distribution.
View Article and Find Full Text PDFISME J
January 2024
Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal, 643, Prevosti Building, Floor 0. Barcelona E-08028, Spain.
The order Crassvirales, which includes the prototypical crAssphage (p-crAssphage), is predominantly associated with humans, rendering it the most abundant and widely distributed group of DNA phages in the human gut. The reported human specificity and wide global distribution of p-crAssphage makes it a promising human fecal marker. However, the specificity for the human gut as well as the geographical distribution around the globe of other members of the order Crassvirales remains unknown.
View Article and Find Full Text PDFISME J
January 2024
Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic.
Bacteriophages are abundant components of vertebrate gut microbial communities, impacting bacteriome dynamics, evolution, and directly interacting with the superhost. However, knowledge about gut phageomes and their interaction with bacteriomes in vertebrates under natural conditions is limited to humans and non-human primates. Widely used specific-pathogen-free (SPF) mouse models of host-microbiota interactions have altered gut bacteriomes compared to wild mice, and data on phageomes from wild or other non-SPF mice are lacking.
View Article and Find Full Text PDFWater Res
November 2024
Department of Food Science & Technology, Chungnam National University, Daejeon, Republic of Korea. Electronic address:
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