Linked Life Data

7873525

Source:http://linkedlifedata.com/resource/pubmed/id/7873525

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1995-4-4
pubmed:abstractText
D-Glutamate is an essential component of the bacterial peptidoglycan. In Escherichia coli, the biosynthesis of D-glutamate is catalyzed by a glutamate racemase (encoded by the dga gene) and is regulated by UDP-N-acetylmuramyl-L-alanine [Doublet et al. (1994) Biochemistry 33, 5285], a bacterial peptidoglycan subunit precursor. Investigation was conducted to elucidate the interaction between the enzyme and its regulator. Whole and N-terminal truncated enzymes, encoded by individual constructs containing either a full-length or an N-terminal truncated dga gene, were evaluated. In the absence of the regulator, the purified whole enzyme showed a low-level basal racemase activity for which a Km value of 18.9 mM and a Vmax of 0.4 mumol/(min.mg) were determined, using D-glutamate as the substrate. Using the same substrate, in the presence of 6.5 microM UDP-N-acetylmuramyl-L-alanine, a Km value of 4.2 mM and a Vmax of 34 mumol/(min.mg) were measured. Similar kinetic parameters for the activated enzyme were obtained using L-glutamate as the substrate. The N-terminal truncated E. coli enzyme, with a 21 amino acid region removed, is similar in size to the Pediococcus pentosaceus glutamate racemase. Effects of the regulator on the full-length and the N-terminal truncated enzyme in the dialyzed cell lysate were compared. A host cell line, E. coli WM335 delta recA, containing a nonfunctional chromosomal dga gene was used to minimize the background interference. With 6.5 microM regulator added, the N-terminal truncated enzyme displayed a loss of more than 80% of the activity compared to the full-length enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
34
pubmed:geneSymbol
dga
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2464-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:7873525-Amino Acid Isomerases, pubmed-meshheading:7873525-Amino Acid Sequence, pubmed-meshheading:7873525-Base Sequence, pubmed-meshheading:7873525-Cloning, Molecular, pubmed-meshheading:7873525-DNA, Bacterial, pubmed-meshheading:7873525-DNA Primers, pubmed-meshheading:7873525-Enzyme Activation, pubmed-meshheading:7873525-Escherichia coli, pubmed-meshheading:7873525-Genes, Bacterial, pubmed-meshheading:7873525-Kinetics, pubmed-meshheading:7873525-Molecular Sequence Data, pubmed-meshheading:7873525-Mutagenesis, Site-Directed, pubmed-meshheading:7873525-Pediococcus, pubmed-meshheading:7873525-Peptidoglycan, pubmed-meshheading:7873525-Sequence Homology, Amino Acid, pubmed-meshheading:7873525-Substrate Specificity, pubmed-meshheading:7873525-Uridine Diphosphate N-Acetylmuramic Acid
pubmed:year
1995
pubmed:articleTitle
UDP-N-acetylmuramyl-L-alanine functions as an activator in the regulation of the Escherichia coli glutamate racemase activity.
pubmed:affiliation
Department of Microbiology, Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, Connecticut 06492.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't