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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-7-27
pubmed:abstractText
Two plasmids were isolated containing oppositely oriented gamma-delta insertions between the wild-type transcription initiation site of the nifHDKY operon and the nifH coding sequence. The nifHDKY promoter of Klebsiella pneumoniae, similar to other nitrogen fixation (nif) promoters, normally requires the products of ntrA and nifA for activity. Mutations that allowed constitutive expression of the nifHDKY operon were searched for by transforming a plasmid, containing the regulatory region of this operon followed by an in-frame nifH'-'lacZ fusion, into a Lac- Escherichia coli strain (which contains no nifA) and screening for Lac+ derivatives. The plasmids described here were isolated from such derivatives and directed the constitutive expression of beta-galactosidase. Deletion analysis indicated that gamma-delta promoters other than those transcribing tnpA and tnpR were involved in this expression. Nuclease S1 mapping revealed outward-reading transcription initiation sites in both the gamma end and the delta end of the transposon. Most interestingly, one initiation site on each end was located in corresponding positions within the terminal inverted repeats. The sites were in the center of the longest sequence, of 12 bp, contiguously conserved between the terminal inverted repeats of gamma-delta and the related transposon Tn3. In gamma-delta and Tn3, this sequence has been recently implicated in transposase binding. These results suggest a possible interrelationship between transcription from the "end" promoters and transposition.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:volume
216
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
138-43
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Outreading promoters are located at both ends of the gamma-delta transposon.
pubmed:affiliation
Biochemistry Department, Weizmann Institute of Science, Rehouot, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't