Linked Life Data

3307905

Source:http://linkedlifedata.com/resource/pubmed/id/3307905

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1987-11-16
pubmed:abstractText
Optically detected magnetic resonance (ODMR) methods were employed to study three single-stranded DNA binding (SSB) proteins encoded by plasmids of enteric bacteria: pIP71a, R64, and F. Equilibrium binding isotherms obtained by fluorescence titrations reveal that the complexes of the plasmid SSB proteins with heavy atom modified polynucleotides are readily disrupted by salt. Since all the plasmid SSB proteins show limited solubility at low ionic strength (pIP71a greater than R64 greater than F), we were able to bind only the pIP71a protein to mercurated poly(uridylic acid) [poly(5-HgU)] and brominated poly(uridylic acid) [poly(5-BrU)]. ODMR results reveal the existence of at least one heavy atom perturbed, red-shifted, stacked Trp residue in these complexes. Amplitude-modulated phosphorescence microwave double resonance spectra display selectively the phosphorescence associated with Hg-perturbed Trp residue(s) in the pIP71a SSB protein-poly(5-HgU) complex, which has a broad, red-shifted 0,0-band. Our results suggest that Trp-135 in Escherichia coli SSB, which is absent in the plasmid-encoded SSB proteins, is located in a polar environment and is not involved in stacking interactions with the nucleotide bases. Phosphorescence spectra and lifetime measurements of the pIP71a SSB protein-poly (5-BrU) complex show that at least one Trp residue in the complex does not undergo stacking. This sets a higher limit of two stacking interactions of Trp residues with nucleotide bases in complexes of pIP71a SSB with single-stranded polynucleotides.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3347-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Optically detected magnetic resonance of tryptophan residues in complexes formed between a bacterial single-stranded DNA binding protein and heavy atom modified poly(uridylic acid).
pubmed:affiliation
Chemistry Department, University of California, Davis 95616.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't