Linked Life Data

3044925

Source:http://linkedlifedata.com/resource/pubmed/id/3044925

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-9-29
pubmed:abstractText
The four general transaminases of Escherichia coli K-12 have overlapping, but discrete, substrate specificities and participate in the final step in the synthesis of at least seven different amino acids. Through the use of strains that have mutations in one or more transaminase genes and carry a different wild-type (wt) gene on a multicopy plasmid, it was possible to detect instances in which an amplified wt gene suppressed nonallelic mutations. In these cases, overproduction of the enzyme permitted a broader range of substrates to be used at physiologically significant levels, either because a low catalytic efficiency (in the case analyzed here) or a low affinity of the enzyme towards the substrate prevented its effective utilization under normal conditions. Consequently, by compensating for a low catalytic reaction rate, enzyme overproduction circumvents the original lesion and restores biosynthetic activity to the mutant strain. The suppression of a mutation in one gene by amplified copies of a different wt gene is termed 'multicopy suppression'. This phenomenon is useful for detecting poorly expressed genes, for detecting duplicate genes, for identifying secondary functions of the products of known genes, and for elucidating the metabolic role of the product of the suppressed gene.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0378-1119
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
195-202
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Acquisition of new metabolic capabilities: multicopy suppression by cloned transaminase genes in Escherichia coli K-12.
pubmed:affiliation
Department of Molecular and Cell Biology, University of Connecticut, Storrs 06268.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.