Linked Life Data

7877490

Source:http://linkedlifedata.com/resource/pubmed/id/7877490

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-3-31
pubmed:abstractText
The structural genes for nitrogenase, nifK, nifD, and nifH, are crucial for nitrogen fixation. Previous phylogenetic analysis of the amino acid sequence of nifH suggested that this gene had been horizontally transferred from a proteobacterium to the gram-positive/cyanobacterial clade, although the confounding effects of paralogous comparisons made interpretation of the data difficult. An additional test of nif gene horizontal transfer using nifD was made, but the NifD phylogeny lacked resolution. Here nif gene phylogeny is addressed with a phylogenetic analysis of a third and longer nif gene, nifK. As part of the study, the nifK gene of the key taxon Frankia was sequenced. Parsimony and some distance analyses of the nifK amino acid sequences provide support for vertical descent of nifK, but other distance trees provide support for the lateral transfer of the gene. Bootstrap support was found for both hypotheses in all trees; the nifK data do not definitively favor one or the other hypothesis. A parsimony analysis of NifH provides support for horizontal transfer in accord with previous reports, although bootstrap analysis also shows some support for vertical descent of the orthologous nifH genes. A wider sampling of taxa and more sophisticated methods of phylogenetic inference are needed to understand the evolution of nif genes. The nif genes may also be powerful phylogenetic tools. If nifK evolved by vertical descent, it provides strong evidence that the cyanobacteria and proteobacteria are sister groups to the exclusion of the firmicutes, whereas 16S rRNA sequences are unable to resolve the relationships of these three major eubacterial lineages.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0737-4038
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:geneSymbol
nif, nifH, nifK
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16-27
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Assessing horizontal transfer of nifHDK genes in eubacteria: nucleotide sequence of nifK from Frankia strain HFPCcI3.
pubmed:affiliation
Department of Biology, University of California, Los Angeles 90024-1606.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't