Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-1-17
pubmed:abstractText
Hfq is a nucleic acid-binding protein that functions as a global regulator of gene expression by virtue of its interactions with several small, non-coding RNA species. Originally identified as an Escherichia coli host factor required for RNA phage Qbeta replication, Hfq is now known to post-transcriptionally regulate bacterial gene expression by modulating both mRNA stability and translational activity. Recently shown to be a member of the diverse Sm protein family, Hfq adopts the OB-like fold typical of other Sm and Sm-like (Lsm) proteins, and also assembles into toroidal homo-oligomers that bind single-stranded RNA. Similarities between the structures, functions, and evolution of Sm/Lsm proteins and Hfq are continually being discovered, and we now report an additional, unexpected biophysical property that is shared by Hfq and other Sm proteins: E.coli Hfq polymerizes into well-ordered fibres whose morphologies closely resemble those found for Sm-like archaeal proteins (SmAPs). However, the hierarchical assembly of these fibres is dissimilar: whereas SmAPs polymerize into polar tubes (and striated bundles of such tubes) by head-to-tail stacking of individual homo-heptamers, helical Hfq fibres are formed by cylindrical slab-like layers that consist of 36 subunits arranged as a hexamer of Hfq homo-hexamers (i.e. protofilaments in a 6 x 6 arrangement). The different fibrillar ultrastructures formed by Hfq and SmAP are presented and examined herein, with the overall goal of elucidating another similarity amongst the diverse members of the Sm protein family.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
356
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
86-96
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Three-dimensional structures of fibrillar Sm proteins: Hfq and other Sm-like proteins.
pubmed:affiliation
Institut de Biologie Physico-Chimique, CNRS UPR 9073 conventionnée avec l'université Paris 7, 13 rue P. et M. Curie, 75005 Paris, France. veronique.arlusion@ibpc.fr
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't