Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2005-8-22
pubmed:abstractText
The chromosomal YoeB-YefM toxin-antitoxin module common to numerous strains of bacteria is presumed to have a significant role in survival under stringent conditions. Recently we showed that the purified YefM antitoxin is a natively unfolded protein, as we previously reported for the Phd antitoxin in the P1 phage Doc-Phd toxin-antitoxin system. Here we report the purification and structural properties of the YoeB toxin and present physical evidence for the existence of a tight YoeB. YefM polypeptide complex in solution. YoeB and YefM proteins co-eluted as single peaks in sequential Ni-affinity FPLC and Q-Sepharose ion-exchange chromatography implying the formation of a YoeB. YefM complex. The unstable antitoxin was removed from the mixture by natural proteolysis, and the residual YoeB protein was purified using ion exchange chromatography. Fluorescence anisotropy studies of the purified YoeB and YefM proteins showed a 2:1 stoichiometry of the complex, providing direct evidence for a physical complex between the proteins. Near- and far-UV circular dichroism spectroscopy of the purified toxin revealed that, similar to the Doc toxin, YoeB is a well-folded protein. Thermal denaturation experiments confirmed the conformational stability of the YoeB toxin, which underwent reversible thermal unfolding at temperatures up to 56 degrees C. The thermodynamic features of the toxin-antitoxin complex were similar. Taken together, our results support the notion of a correlation between differential physiological and structural stability in toxin-antitoxin modules.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30063-72
pubmed:dateRevised
2009-11-3
pubmed:meshHeading
pubmed-meshheading:15980067-Anisotropy, pubmed-meshheading:15980067-Bacterial Toxins, pubmed-meshheading:15980067-Blotting, Western, pubmed-meshheading:15980067-Chromatography, Ion Exchange, pubmed-meshheading:15980067-Circular Dichroism, pubmed-meshheading:15980067-Cloning, Molecular, pubmed-meshheading:15980067-Dimerization, pubmed-meshheading:15980067-Dose-Response Relationship, Drug, pubmed-meshheading:15980067-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:15980067-Escherichia coli, pubmed-meshheading:15980067-Escherichia coli Proteins, pubmed-meshheading:15980067-Hot Temperature, pubmed-meshheading:15980067-Microscopy, Fluorescence, pubmed-meshheading:15980067-Peptides, pubmed-meshheading:15980067-Protein Binding, pubmed-meshheading:15980067-Protein Conformation, pubmed-meshheading:15980067-Protein Denaturation, pubmed-meshheading:15980067-Protein Folding, pubmed-meshheading:15980067-Protein Structure, Tertiary, pubmed-meshheading:15980067-Spectrometry, Fluorescence, pubmed-meshheading:15980067-Spectrophotometry, pubmed-meshheading:15980067-Temperature, pubmed-meshheading:15980067-Thermodynamics, pubmed-meshheading:15980067-Time Factors, pubmed-meshheading:15980067-Toxins, Biological, pubmed-meshheading:15980067-Ultraviolet Rays
pubmed:year
2005
pubmed:articleTitle
The YoeB toxin is a folded protein that forms a physical complex with the unfolded YefM antitoxin. Implications for a structural-based differential stability of toxin-antitoxin systems.
pubmed:affiliation
Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't