Linked Life Data

2464692

Source:http://linkedlifedata.com/resource/pubmed/id/2464692

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1989-3-17
pubmed:abstractText
The spc ribosomal protein operon of Escherichia coli is feedback-regulated by ribosomal protein S8, a translational repressor. We have analyzed the region of the spc mRNA that is responsible for this regulation. First, we have established that the S8 target site on the mRNA is near the translation start site of the third gene encoding ribosomal protein L5 in the operon. This was done by constructing hybrid plasmids carrying spc operon ribosomal protein genes under lac transcriptional control, as well as their deletion derivatives, and carrying out both in vivo and in vitro protein synthesis experiments. Next, the secondary structure of this region was studied by analyzing 5' end-labeled RNA synthesized from the phage SP6 promoter using structure-specific nucleases. A secondary structure model consistent with the results was deduced with the aid of a computer prediction of RNA folding. In addition, we cloned and sequenced the corresponding region from Salmonella typhimurium, Proteus vulgaris and Serratia marcescens and found five "compensating" substitutions that support some of the deduced helical structures of mRNA. None of the base changes was inconsistent with the deduced secondary structure model. Finally, site-directed mutagenesis experiments have identified bases important for regulation, including two base-paired sites representing each of two helical regions. This has led to the conclusion that some specific nucleotide residues located between these two helical regions are directly involved in S8 recognition, and that the function of the two helical regions is to maintain the proper orientation of these nucleotide residues. Comparison of the structure of the S8 target site on the spc mRNA with the known S8 binding site on rRNA has revealed a striking similarity in both primary and secondary structures. In particular, primary sequences of rRNA conserved among distantly related bacterial species in this region is found to be identical with the sequences at the corresponding positions in mRNA. These results suggest that the same structural features of the S8 repressor protein are involved in the interaction with both 16 S rRNA and the mRNA target site.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
204
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
309-29
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Translational regulation of the spc operon in Escherichia coli. Identification and structural analysis of the target site for S8 repressor protein.
pubmed:affiliation
Department of Biological Chemistry, University of California-Irvine 92717.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.