Linked Life Data

10731411

Source:http://linkedlifedata.com/resource/pubmed/id/10731411

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-5-1
pubmed:databankReference
pubmed:abstractText
DEAD-box RNA helicases, by unwinding duplex RNA in bacteria and eukaryotes, are involved in essential cellular processes, including translation initiation and ribosome biogenesis, and have recently been implicated in enabling bacteria to survive cold-shock and grow at low temperature. Despite these critical physiological roles, they have not been characterized in archaea. Due to their presumed importance in removing cold-stabilised secondary structures in mRNA, we have characterised a putative DEAD-box RNA helicase gene (deaD) from the Antarctic methanogen, Methanococcoides burtonii. The encoded protein, DeaD is predicted to contain a core element involved in ATP hydrolysis and RNA-binding, and an unusual C-terminal domain that contains seven perfect, trideca-peptide, direct repeats that may be involved in RNA binding. Alignment and phylogenetic analyses were performed on the core regions of the M. burtonii and other DEAD-box RNA helicases. These revealed a loose but consistent clustering of archaeal and bacterial sequences and enabled the generation of a prokaryotic-specific consensus sequence. The consensus highlights the importance of residues other than the eight motifs that are often associated with DEAD-box RNA helicases, as well as de-emphasising the importance of the "A" residue within the "DEAD" motif. Cells growing at 4 degrees C contained abundant levels of deaD mRNA, however no mRNA was detected in cells growing at 23 degrees C (the optimal temperature for growth). The transcription initiation site was mapped downstream from an archaeal box-A element (TATA box), which preceded a long (113 nucleotides) 5'-untranslated region (5'-UTR). Within the 5'-UTR was an 11 bp sequence that closely matches (nine out of 11) cold-box elements that are present in the 5'-UTRs of cold-shock induced genes from bacteria. To determine if the archaeal 5'-UTR performs an analagous function to the bacterial 5'-UTRs, the archaeal deaD 5'-UTR was transcribed in E. coli under the control of the cspA promoter and transcriptional terminator. It has previously been reported that overexpression of the cspA 5'-UTR leads to an extended cold-shock response due to the 5'-UTR titrating cellular levels of a cold-shock repressor protein(s). In our hands, the cold-shock protein profiles resulting from overexpression of Escherichia coli cspA and M. burtonii deaD 5'-UTRs were similar, however they did not differ from those for the overexpression of a control plasmid lacking a 5'-UTR. In association with other recent data from E. coli, our results indicate that the role of the 5'-UTR in gene regulation is presently unclear. Irrespective of the mechanisms, it is striking that highly similar 5'-UTRs with cold-box elements are present in cold induced genes from E. coli, Anabaena and M. burtonii. This is the first study examining low temperature regulation in archaea and provides initial evidence that gene expression from a cold adapted archaeon involves a bacterial-like transcriptional regulatory mechanism. In addition, it provides the foundation for further studies into the function and regulation of DEAD-box RNA helicases in archaea, and in particular, their roles in low temperature adaptation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
297
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
553-67
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:10731411-5' Untranslated Regions, pubmed-meshheading:10731411-Adaptation, Physiological, pubmed-meshheading:10731411-Amino Acid Motifs, pubmed-meshheading:10731411-Amino Acid Sequence, pubmed-meshheading:10731411-Antarctic Regions, pubmed-meshheading:10731411-Archaeal Proteins, pubmed-meshheading:10731411-Bacterial Proteins, pubmed-meshheading:10731411-Base Sequence, pubmed-meshheading:10731411-Cloning, Molecular, pubmed-meshheading:10731411-Cold Temperature, pubmed-meshheading:10731411-Consensus Sequence, pubmed-meshheading:10731411-Gene Dosage, pubmed-meshheading:10731411-Gene Expression Regulation, Archaeal, pubmed-meshheading:10731411-Genes, Archaeal, pubmed-meshheading:10731411-Methanosarcinaceae, pubmed-meshheading:10731411-Molecular Sequence Data, pubmed-meshheading:10731411-Phylogeny, pubmed-meshheading:10731411-RNA, Messenger, pubmed-meshheading:10731411-RNA Helicases, pubmed-meshheading:10731411-Response Elements, pubmed-meshheading:10731411-Sequence Alignment, pubmed-meshheading:10731411-Transcription, Genetic
pubmed:year
2000
pubmed:articleTitle
Low temperature regulated DEAD-box RNA helicase from the Antarctic archaeon, Methanococcoides burtonii.
pubmed:affiliation
School of Microbiology and Immunology, The University of New South Wales, Sydney, UNSW, 2052, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't