Linked Life Data

8706840

Source:http://linkedlifedata.com/resource/pubmed/id/8706840

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-9-10
pubmed:abstractText
The phylogenetic distribution of divergently related protein families into the three domains of life (archaea, bacteria and eukaryotes) can signify the presence or absence of entire cellular processes in these domains and their ancestors. We can thus study the emergence of the major transitions during cellular evolution, and resolve some of the controversies surrounding the evolutionary status of archaea and the origins of the eukaryotic cell. In view of the ongoing projects that sequence the complete genomes of several Archaea, this work forms a testable prediction when the genome sequences become available. Using the presence of the protein families as taxonomic traits, and linking them to biochemical pathways, we are able to reason about the presence of the corresponding cellular processes in the last universal ancestor of contemporary cells. The analysis shows that metabolism was already a complex network of reactions which included amino acid, nucleotide, fatty acid, sugar and coenzyme metabolism. In addition, genetic processes such as translation are conserved and close to the original form. However, other processes such as DNA replication and repair or transcription are exceptional and seem to be associated with the structural changes that drove eukaryotes and bacteria away from their common ancestor. There are two major hypotheses in the present work: first, that archaea are probably closer to the last universal ancestor than any other extant life form, and second, that the major cellular processes were in place before the major splitting. The last universal ancestor had metabolism and translation very similar to the contemporary ones, while having an operonic genome organization and archaean-like transcription. Evidently, all cells today contain remnants of the primordial genome of the last universal ancestor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
390
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
119-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
The emergence of major cellular processes in evolution.
pubmed:affiliation
AI Center, SRI International, Menlo Park, CA 94025-3493, USA. ouzounis@ai.sri.com
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't