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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1996-4-11
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pubmed:databankReference | |
pubmed:abstractText |
A 14.3 kb DNA fragment from Klebsiella oxytoca M5a1 has been cloned and shown to provide Escherichia coli with the capacity for growth on alpha- and beta-cyclodextrins. This fragment is located immediately upstream of the previously identified cgt gene coding for cyclodextrin glycosyltransferase. It contains ten genes (cym) organised in two divergently oriented clusters separated by a non-coding region of 419 bp. Four of the genes code for products homologous to the maltose and linear maltodextrin uptake system, another one for a putative cytoplasmic cyclodextrinase. The cym genes of K. oxytoca are distinct and different from the mal genes; cym mutations do not affect maltose catabolism. On the other hand, whereas mutations in the maltose/maltodextrin-uptake genes do not influence cyclodextrin metabolism, a mutation inactivating the malPQ genes coding for maltodextrin phosphorylase and amylomaltase does. Cyclodextrin catabolism is independent of the presence of a functional cyclodextrin glycosyltransferase but degradation of starch and gamma-cyclodextrins requires the activity of this enzyme. The results indicate the existence of a novel starch degradation pathway which involves the extracellular conversion of starch into cyclodextrins by cyclodextrin glycosyltransferase, uptake of the cyclodextrins by a specific uptake system and intracellular linearisation by a cyclodextrinase. The malto-oligosaccharides produced are then channelled into the maltodextrin-degradation route involving the activity of maltodextrin phosphorylase and amylomaltase.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0022-2836
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
23
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pubmed:volume |
256
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
279-91
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pubmed:dateRevised |
2000-12-18
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pubmed:meshHeading |
pubmed-meshheading:8594196-Amino Acid Sequence,
pubmed-meshheading:8594196-Bacterial Proteins,
pubmed-meshheading:8594196-Base Sequence,
pubmed-meshheading:8594196-Carbohydrate Sequence,
pubmed-meshheading:8594196-Chromosomes, Bacterial,
pubmed-meshheading:8594196-Cloning, Molecular,
pubmed-meshheading:8594196-Cyclodextrins,
pubmed-meshheading:8594196-Escherichia coli,
pubmed-meshheading:8594196-Genes, Bacterial,
pubmed-meshheading:8594196-Glucosyltransferases,
pubmed-meshheading:8594196-Klebsiella,
pubmed-meshheading:8594196-Molecular Sequence Data,
pubmed-meshheading:8594196-Sequence Homology, Amino Acid,
pubmed-meshheading:8594196-Transformation, Genetic
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pubmed:year |
1996
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pubmed:articleTitle |
Genetics of a novel starch utilisation pathway present in Klebsiella oxytoca.
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pubmed:affiliation |
Lehrstuhl für Mikrobiologie der Universität München, Munich, Germany
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pubmed:publicationType |
Journal Article
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