Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-7-18
pubmed:abstractText
Nodulation (nod) genes in Rhizobium meliloti are transcriptionally induced by flavonoid signal molecules, such as luteolin, produced by its symbiotic host plant, alfalfa. This induction depends on expression of nodD. Upstream of three inducible nod gene clusters, nodABC, nodFE, and nodH, is a highly conserved sequence referred to as a 'nod box.' The upstream sequences have no other obvious similarity. We have found that DNA fragments containing the regions upstream of all three inducible transcripts show altered electrophoretic mobility when treated with R. meliloti extracts. The ability of the extracts to interact specifically with these DNAs correlated with the genetic dosage of nodD1 or nodD3 and with the presence and concentration of the nodD1 or nodD3 protein (NodD1 or NodD3) in the extracts. Antiserum specific to NodD was used to construct an immunoaffinity column that permitted a substantial purification of NodD1; this preparation of NodD1 also displayed specific binding to restriction fragments containing DNA sequences found upstream of inducible nod genes. In addition, NodD-specific antiserum removed the specific DNA-binding activity from total Rhizobium cell extracts. The interaction of total extracts and of partially purified NodD protein with nod promoter sequences was competitive with an oligonucleotide representing the 3' 25-bp portion of the nod box. The interaction of R. meliloti extracts and NodD1 protein with nod gene upstream regions occurred independently of exposure of cells or extracts to flavone inducer.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0890-9369
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
282-93
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Specific binding of proteins from Rhizobium meliloti cell-free extracts containing NodD to DNA sequences upstream of inducible nodulation genes.
pubmed:affiliation
Department of Biological Sciences, Stanford University, California 94305-5020.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.