Linked Life Data

17388571

Source:http://linkedlifedata.com/resource/pubmed/id/17388571

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2007-4-17
pubmed:databankReference
pubmed:abstractText
O-Acetylpeptidoglycan esterase from Neisseria gonorrheae FA1090 is similar in sequence to family CE-3 carbohydrate esterases of the CAZy classification system, and it functions to release O-linked acetyl groups from the C-6 position of muramoyl residues in O-acetylated peptidoglycan. Here, we characterize the peptidoglycan of N. gonorrheae FA1090 as being O-acetylated and find that it serves as a substrate for the esterase. The influence of pH on the activity of O-acetylpeptidoglycan esterase was determined, and pKa values of 6.38 and 6.78 for the enzyme-substrate complex (VEt-1) and free enzyme (VEt-1KM-1), respectively, were calculated. The enzyme was inactivated by sulfonyl fluorides but not by EDTA. Multiple-sequence alignment of the O-acetylpeptidoglycan esterase family 1 enzymes with members of the CE-3 enzymes and protein modeling studies identified Ser80, Asp366, and His369 as three invariant amino acid residues that could potentially serve as a catalytic triad. Replacement of each with alanine was accomplished by site-directed mutagenesis, and the resulting mutant proteins were purified to apparent homogeneity. The specific activity of each of the three esterase derivatives was greatly reduced on O-acetylpeptidoglycan. Using the artificial substrate p-nitrophenyl acetate, a kinetic analysis revealed that the turnover number (VEt-1) but not KM was affected by the replacements. These data thus indicate that N. gonorrheae O-acetylpeptidoglycan esterase, and by analogy the CE-3 family of enzymes, function as serine esterases involving a Ser-His-Asp catalytic triad.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4932-41
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Neisseria gonorrheae O-acetylpeptidoglycan esterase, a serine esterase with a Ser-His-Asp catalytic triad.
pubmed:affiliation
Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't