@article{Weidenbach_Nickel_Neve-MetSV_novel_archa-2017,
author = {Weidenbach, Katrin and Nickel, Lisa and Neve, Horst and 
          Alkhnbashi, Omer S. and Kunzel, Sven and Kupczok, Anne and 
          Bauersachs, Thorsten and Cassidy, Liam and Tholey, Andreas 
          and Backofen, Rolf and Schmitz, Ruth A.},
title = {{MetSV}, a novel archaeal lytic virus targeting 
         {Methanosarcina} strains},
journal = {J Virol},
year = {2017},
doi = {10.1128/JVI.00955-17},
volume = {},
user = {alkhanbo},
pmid = {28878086},
pages = {},
number = {},
issn = {1098-5514},
abstract = {A novel archaeal lytic virus targeting species of the genus 
            Methanosarcina was isolated using Methanosarcina mazei 
            strain Go1 as host. Due to its spherical morphology the 
            virus was designated Methanosarcinaspherical virus (MetSV). 
            Molecular analysis demonstrated that MetSV contains double 
            stranded linear DNA with a genome size of 10,567 bp 
            containing 22 open reading frames (ORFs) all oriented in the 
            same direction. Functions were predicted for some of these 
            ORFs, i. e. like DNA polymerase, ATPase, DNA-binding 
            protein, as well as envelope (structural) protein. 
            MetSV-derived spacers in CRISPR loci were detected in 
            several published Methanosarcina draft genomes using 
            bioinformatic tools, revealing the potential PAM motif 
            (TTA/T). Transcription and expression of several predicted 
            viral ORFs were validated by RT-PCR, PAGE analysis and LC-MS 
            based proteomics. Analysis of core lipids by APCI mass 
            spectrometry showed that MetSV and M. mazei both contain 
            archaeol and glycerol dialkyl glycerol tetraether without 
            cyclopentane moiety (GDGT-0). The MetSV host range is 
            limited to Methanosarcina strains growing as single cells 
            (M. mazei, M. bakeri and M. soligelidi). In contrast, 
            strains growing as sarcina-like aggregates were apparently 
            protected from infection. Heterogeneity related to 
            morphology phases in M. mazei cultures allowed acquisition 
            of resistance to MetSV after challenge by growing as 
            sarcina-like aggregates. CRISPR/Cas mediated resistance was 
            excluded since neither of the two CRISPR arrays showed 
            MetSV-derived spacer acquisition. Based on these findings, 
            we propose that changing the morphology from single cells to 
            sarcina-like aggregates upon rearrangement of the envelope 
            structure prevents infection and subsequent lysis by 
            MetSV.IMPORTANCE Methanoarchaea are among the most abundant 
            organisms on the planet since they are present in high 
            numbers in major anaerobic environments. They convert 
            various carbon sources e.g. acetate, methylamines or 
            methanol to methane and carbon dioxide, thus they have a 
            significant impact on the emission of major greenhouse 
            gases. Today very little is known about viruses specifically 
            infecting methanoarchaea, which most probably impact the 
            abundance of methanoarchaea in microbial consortia. Here we 
            characterize the first identified Methanosarcina infecting 
            virus (MetSV) and show a mechanism for acquiring resistance 
            against MetSV. Based on our results we propose that growth 
            as sarcina-like aggregates prevents infection and subsequent 
            lysis. These findings allow new insights into virus-host 
            relationship in methanogenic community structures, their 
            dynamics and their phase heterogeneity. Moreover, the 
            availability of a specific virus provides new possibilities 
            to deepen our knowledge on defence mechanisms of potential 
            hosts and offers tools for genetic manipulation.}
}