Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-7-18
pubmed:databankReference
http://linkedlifedata.com/resource/pubmed/xref/GENBANK/L43550, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/L43551, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/L43555, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/L46355, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/L46356, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/L46357, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/L46358, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36732, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36733, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36734, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36735, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36736, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36737, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36738, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36739, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36740, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36741, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36742, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36743, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36744, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36745, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36746, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36747, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36748, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36749, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36750, http://linkedlifedata.com/resource/pubmed/xref/GENBANK/U36751
pubmed:abstractText
The bacterial endosymbionts (Buchnera) from the aphids Rhopalosiphum padi, R. maidis, Schizaphis graminum, and Acyrthosiphon pisum contain the genes for anthranilate synthase (trpEG) on plasmids made up of one or more 3.6-kb units. Anthranilate synthase is the first as well as the rate-limiting enzyme in the tryptophan biosynthetic pathway. The amplification of trpEG on plasmids may result in an increase of enzyme protein and overproduction of this essential amino acid, which is required by the aphid host. The nucleotide sequence of trpEG from endosymbionts of different species of aphids is highly conserved, as is an approximately 500-bp upstream DNA segment which has the characteristics of an origin of replication. Phylogenetic analyses were performed using trpE and trpG from the endosymbionts of these four aphids as well as from the endosymbiont of Schlechtendalia chinensis, in which trpEG occurs on the chromosome. The resulting phylogeny was congruent with trees derived from sequences of two chromosome-located bacterial genes (part of trpB and 16S ribosomal DNA). In turn, trees obtained from plasmid-borne and bacterial chromosome-borne sequences were congruent with the tree resulting from phylogenetic analysis of three aphid mitochondrial regions (portions of the small and large ribosomal DNA subunits, as well as cytochrome oxidase II). Congruence of trees based on genes from host mitochondria and from bacteria adds to previous support for exclusively vertical transmission of the endosymbionts within aphid lineages. Congruence with trees based on plasmid-borne genes supports the origin of the plasmid-borne trpEG from the chromosomal genes of the same lineage and the absence of subsequent plasmid exchange among endosymbionts of different species of aphids.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2844
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
414-21
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
The tryptophan biosynthetic pathway of aphid endosymbionts (Buchnera): genetics and evolution of plasmid-associated anthranilate synthase (trpEG) within the aphididae.
pubmed:affiliation
Microbiology Section, University of California, Davis 95616-8665, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't