Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-2-2
pubmed:databankReference
pubmed:abstractText
D-aspartate is present at high concentrations in the tissues of Scapharca broughtonii, and its production depends on aspartate racemase. This enzyme is the first aspartate racemase purified from animal tissues and unique in its pyridoxal 5'-phosphate (PLP)-dependence in contrast to microbial aspartate racemases thus far characterized. The enzyme activity is markedly increased in the presence of AMP and decreased in the presence of ATP. To analyze the structure-function relationship of the enzyme further, we cloned the cDNA of aspartate racemase, and then purified and characterized the recombinant enzyme expressed in Escherichia coli. The cDNA included an open reading frame of 1,017 bp encoding a protein of 338 amino acids, and the deduced amino acid sequence contained a PLP-binding motif. The sequence exhibits the highest identity (43-44%) to mammalian serine racemase, followed mainly by threonine dehydratase. These relationships are fully supported by phylogenetic analyses of the enzymes. The active recombinant aspartate racemase found in the Escherichia coli extract represented about 10% of total bacterial protein and was purified to display essentially identical physicochemical and catalytic properties with those of the native enzyme. In addition, the enzyme showed a dehydratase activity toward L-threo-3-hydroxyaspartate, similar to the mammalian serine racemase that produces pyruvate from D- and L-serine.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
139
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
235-44
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Cloning and expression of the pyridoxal 5'-phosphate-dependent aspartate racemase gene from the bivalve mollusk Scapharca broughtonii and characterization of the recombinant enzyme.
pubmed:affiliation
Department of Environmental Systems Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan.
pubmed:publicationType
Journal Article, Comparative Study