Linked Life Data

9421930

Source:http://linkedlifedata.com/resource/pubmed/id/9421930

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-3-17
pubmed:databankReference
pubmed:abstractText
Mannose-containing polysaccharides are widely distributed in cell walls of higher plants. During endosperm mobilization in germinated tomato seeds (1-->4)-beta-mannan endohydrolases (EC 3.2.1.78) participate in the enzymic depolymerization of these cell wall polysaccharides. A cDNA encoding a (1-->4)-beta-mannanase from the endosperm of germinated tomato (Lycopersicon esculentum Mill.) seeds has been isolated and characterized. The amino acid sequence deduced from the 5'-region of the cDNA exactly matches the sequence of the 65 NH2-terminal amino acids determined directly from the purified enzyme. The mature enzyme consists of 346 amino acid residues, it has a calculated M(r) of 38,950 and an isoelectric point of 5.3. Overall, the enzyme exhibits only 28-30% sequence identity with fungal (1-->4)-beta-mannanases, but more highly conserved regions, which may represent catalytic and substrate-binding domains, can be identified. Based on classification of the tomato (1-->4)-beta-mannanase as a member of the family 5 group of glycosyl hydrolases, Glu-148 and Glu-265 would be expected to be the catalytic acid and the catalytic nucleophile, respectively. Southern hybridization analyses indicate that the enzyme is derived from a family of about four genes. Expression of the genes, as determined by the presence of mRNA transcripts in Northern hybridization analyses, occurs in the endosperm of germinated seeds; no transcripts are detected in hypocotyls, cotyledons, roots or leaves.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
B
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0032-0935
pubmed:author
pubmed:issnType
Print
pubmed:volume
203
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
454-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Molecular cloning of a cDNA encoding a (1-->4)-beta-mannan endohydrolase from the seeds of germinated tomato (Lycopersicon esculentum).
pubmed:affiliation
Department of Botany, University of Guelph, Ontario, Canada. dbewley@uoguelph.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't