Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-9-2
pubmed:abstractText
Four closely related species of yeast possess multicopy nuclear plasmids whose shared molecular architecture demonstrates a common ancestor, despite their lack of discernible DNA sequence homology. Each plasmid encodes three proteins which have equivalent essential functions in plasmid maintenance. These three groups of proteins show markedly different degrees of conservation, so that although we have successfully aligned sequences for two groups, members of the third group have diverged to such an extent that they cannot be aligned. All the proteins are sufficiently different that they function only in conjunction with their encoding plasmid. These proteins have therefore conserved their functional interactions with the relevant DNA sequences of their particular plasmids, despite lack of amino acid sequence conservation. The maintenance of function in the face of DNA sequence divergence is analogous to the coevolution of ribosomal DNA promoters and RNA polymerase I, and suggests that molecular drive may be an important force in the evolution of these plasmids. This view is reinforced by the inconsistent phylogenetic relationships determined from the two alignment sets, and by the contradiction that the two plasmids known to be the closest related taxonomically and by their host interchangeability are suggested to be the most distant by their sequences.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
200
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
601-7
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Unexpected divergence and molecular coevolution in yeast plasmids.
pubmed:affiliation
European Molecular Biology Laboratory, Heidelberg Federal Republic of Germany.
pubmed:publicationType
Journal Article