Linked Life Data

8637923

Source:http://linkedlifedata.com/resource/pubmed/id/8637923

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1369
pubmed:dateCreated
1996-7-11
pubmed:abstractText
The evolution of monomorphic proteins among closely related species has not been examined in detail. To investigate this phenomenon, the glycerol-3-phosphate dehydrogenase (Gpdh) locus was sequence in a broad range of Drosophila species. Although purifying selection to remove amino acid variation is the dominant force in the evolution of Gpdh, some replacements have occurred. The sequences were compared in the context of the phylogeny of the genus, revealing a high proportion of amino acid parallelism and reversal (homoplasy) at four sites. The level of homoplasy is significantly greater than that seen in other proteins for which multiple sequences are available, showing that Gpdh is strongly constrained by both the number of amino acid differences and the types of changes allowed. These four sites evolve at a much higher rate than do the other variable positions in the protein, accounting for half of the interspecific amino acid replacements. However, unlike typical hypervariable sites, where multiple changes to several different amino acids are seen, evolutionary 'flip-flopping' between two amino acid states defines this new class of hypervariable site.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0962-8452
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
393-400
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Excessive homoplasy in an evolutionarily constrained protein.
pubmed:affiliation
Museum of Comparative Zoology Laboratories, Harvard University, Cambridge, Massachusetts 02138, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't