title: Archaeal and eukaryotic homologs of Hfq: A structural and evolutionary perspective on Sm function.
abstract: Hfq and other Sm proteins are central in RNA metabolism, forming an evolutionarily conserved family that plays key roles in RNA processing in organisms ranging from archaea to bacteria to human. Sm-based cellular pathways vary in scope from eukaryotic mRNA splicing to bacterial quorum sensing, with at least one step in each of these pathways being mediated by an RNA-associated molecular assembly built upon Sm proteins. Though the first structures of Sm assemblies were from archaeal systems, the functions of Sm-like archaeal proteins (SmAPs) remain murky. Our ignorance about SmAP biology, particularly vis-à-vis the eukaryotic and bacterial Sm homologs, can be partly reduced by leveraging the homology between these lineages to make phylogenetic inferences about Sm functions in archaea. Nevertheless, whether SmAPs are more eukaryotic (RNP scaffold) or bacterial (RNA chaperone) in character remains unclear. Thus, the archaeal domain of life is a missing link, and an opportunity, in Sm-based RNA biology.
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA, USA.
authors.forename: Cameron
authors.initials: C
authors.lastname: Mura
authors.forename: Peter S
authors.initials: PS
authors.lastname: Randolph
authors.forename: Jennifer
authors.initials: J
authors.lastname: Patterson
authors.forename: Aaron E
authors.initials: AE
authors.lastname: Cozen
mesh_terms: D001105:Archaea / Q000235:genetics / Q000378:metabolism; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D056890:Eukaryota / Q000235:genetics / Q000378:metabolism; D006801:Humans; D010802:Phylogeny; D019642:RNA, Archaeal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D058727:RNA, Small Untranslated / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D019642:RNA, Archaeal; D012333:RNA, Messenger; D058727:RNA, Small Untranslated; D016601:RNA-Binding Proteins; D017411:Ribonucleoproteins, Small Nuclear
keywords: Hfq protein; Lsm; RNA chaperone; RNP assembly; RNP evolution; Sm; Sm fold; archaeal RNA; oligomers