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Gonzalez-Serrano, R.

Publications and source records attributed to Gonzalez-Serrano, R..

3 recordsLinked to original sources

Antarctic Soil Auxiliarome: unraveling the pan-auxiliary metabolic genes catalogue in a transect across different ice-free regions of Antarctica

The Transantarctic Mountains host a significant portion of Antarcticas ice-free soils and support diverse microbial communities, but the role of viruses in these extreme ecosystems remains poorly understood. To address this gap, we conducted the first comprehensive analysis of both RNA and DNA soil viruses across ten locations along a regional-scale latitudinal transect. This study revealed high viral diversity, including the first description of 18 previously unreported viral families in Antarctic soils, alongside significant local viral endemicity. Elevation emerged as the primary driver of viral diversity, while distance to the coast explained the distribution of auxiliary metabolic genes (AMGs), and distance to the sea influenced the metabolic pathways associated with these AMGs. The concept of the "auxiliarome," a pan-AMG catalogue at the community level, underscores the critical role of AMGs in engineering host metabolism. These genes contribute to the metabolism of cofactors and vitamins, amino acids, carbohydrates, and sulfur, as well as ecologically significant traits such as bacterial restriction-modification systems or antibiotic production and resistance. This study expands our understanding of Antarctic soil viruses and highlights their ecological importance in shaping microbial communities and biogeochemical processes in extreme environments.

microbiology↗

A host recognition module shared among distant Alteromonas bacteriophage families features tail fibers with transient chaperone caps

The host recognition modules encoding the injection machinery and receptor binding proteins (RBPs) of bacteriophages are variable genomic units predisposed to mutation and recombination to maintain infectivity toward co-evolving bacterial hosts. In this study, we reveal how Alteromonas mediterranea schitovirus A5 shares its host recognition module, including tail fiber (TF) and cognate chaperone, with phages from distantly related families including Alteromonas myovirus, V22. While the chaperone of V22 is essential for producing active TFs, here we demonstrate production of functional A5 TFs regardless of chaperone co-expression. AlphaFold-generated models of TF and chaperone pairs from phages A5, V22, and other Alteromonas phages reveal how amino acid insertions within both A5-like proteins results in a knob domain duplication in the TF and a {beta}-hairpin "tentacle" extension of the chaperone. These structural modifications are linked to chaperone dependency differences between the A5 and V22 TFs. Structural similarity between the chaperones and intramolecular chaperone domains of other phage RBPs suggests an additional function of these chaperones as transient TF "caps". Finally, our identification of homologous host recognition modules used by morphologically distinct phages implies that HGT and recombination events between unrelated phages may be a more common process than previously thought among Caudoviricetes phages.

microbiology↗

New Viral Biogeochemical Roles Revealed Through Metagenomic Analysis of Lake Baikal

Lake Baikal is the largest body of liquid freshwater on Earth. Previous studies have described the microbial composition of this habitat but the viral communities from this ecosystem have not been characterized in detail. Here we describe the viral diversity of this habitat across depth and seasonal gradients. We discovered 19,475 bona fide viral sequences, which are derived from viruses predicted to infect abundant and ecologically important taxa that reside in Lake Baikal, such as Nitrospirota, Methylophilaceae and Crenarchaeota. Diversity analysis revealed significant changes in viral community composition between epipelagic and bathypelagic zones. Analysis of the gene content of individual viral populations allowed us to describe one of the first bacteriophages that infect Nitrospirota, and their extensive repertoire of auxiliary metabolic genes that might enhance carbon fixation through the reductive TCA cycle. We also described bacteriophages of methylotrophic bacteria with the potential to enhance methanol oxidation and the S-adenosyl-L-methionine cycle. These findings unraveled new ways by which viruses influence the carbon cycle in freshwater ecosystems, namely by using auxiliary metabolic genes that act upon metabolisms of dark carbon fixation and methylotrophy. Therefore, our results shed light on the processes through which viruses can impact biogeochemical cycles of major ecological relevance.

microbiology↗