Linked Life Data

9245815

Source:http://linkedlifedata.com/resource/pubmed/id/9245815

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1997-9-17
pubmed:databankReference
pubmed:abstractText
The inducible acetamidase of Mycobacterium smegmatis NCTC 8159 is expressed at high levels in the presence of a suitable inducer, such as acetamide. The gene and 1.5 kb of upstream sequence had previously been sequenced. A further 1.4 kb of upstream sequence has now been determined, containing an additional ORF on the opposite strand to the acetamidase gene. This ORF has significant homologies to genes encoding regulatory proteins involved in amidase expression in other organisms. Restriction fragments from the 4 kb region were subcloned into a promoter-probe shuttle vector to locate the approximate region of the acetamidase promoter and investigate the mechanism of regulation. An inducible promoter was found to lie in the 1.4 kb region situated 1.5 kb upstream from the acetamidase coding region. Expression of the acetamidase was studied at the protein and mRNA levels. Using immunoblotting, induction of the enzyme was demonstrated in minimal medium containing succinate plus acetamide, but not in a richer medium (Lemco broth) plus acetamide, confirming that regulation of acetamidase expression is mediated by both positive and negative control elements. After induction by acetamide, an increase above basal level could be detected after 1 h for both protein levels (using ELISA) and mRNA levels (using Northern blot analysis), indicating that control of expression is at the mRNA level. The size of the mRNA transcript detected was approximately 1.2 kb, the size of the acetamidase coding region. Since no promoter was identified immediately upstream of the coding region, this raises the possibility that a larger, primary transcript (possibly polycistronic) is cleaved to produce a stable form encoding the acetamidase protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1350-0872
pubmed:author
pubmed:issnType
Print
pubmed:volume
143 ( Pt 7)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2267-76
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Regulation of the inducible acetamidase gene of Mycobacterium smegmatis.
pubmed:affiliation
Laboratory for Leprosy and Mycobacterial Research, National Institute for Medical Research, Mill Hill, London, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't