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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 7
pubmed:dateCreated
2007-6-29
pubmed:abstractText
Corynebacterium glutamicum cells growing in medium containing sugars accumulate glycogen in the early exponential-growth phase, and start to degrade this polymer at entry into the stationary phase. In a first attempt to investigate glycogen degradation, the C. glutamicum glgX gene, which encodes a protein with 46 % identity to the isoamylase-type debranching enzyme of Escherichia coli, was analysed, expressed and inactivated. The purified C. glutamicum gene product showed debranching activity towards glycogen, amylopectin and starch. Chromosomal inactivation of glgX in C. glutamicum wild-type led to slower growth and to a higher intracellular glycogen pool throughout growth, when compared to those in the parental strain. This result suggests that glycogen synthesis and degradation occur simultaneously in C. glutamicum. When exposed to hyperosmotic shock, C. glutamicum rapidly degrades glycogen, and at the same time, synthesizes the osmoprotectant trehalose. The glgX mutant, however, synthesized only minor amounts of trehalose throughout cultivation, and its growth ceased after hyperosmotic shock. Taken together, the results indicate that the glgX gene product is essential for glycogen degradation in C. glutamicum, that glycogen is constantly recycled in C. glutamicum, and that it serves as a carbon store for trehalose synthesis via the TreYZ pathway after hyperosmotic shock.
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
153
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2212-20
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
The glgX gene product of Corynebacterium glutamicum is required for glycogen degradation and for fast adaptation to hyperosmotic stress.
pubmed:affiliation
Institute of Microbiology and Biotechnology, University of Ulm, D-89069 Ulm, Germany.
pubmed:publicationType
Journal Article