Linked Life Data

11098133

Source:http://linkedlifedata.com/resource/pubmed/id/11098133

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-1-26
pubmed:abstractText
The primary structures of cis-prenyltransferases are completely different from those of trans-prenyltransferases. To obtain information about amino acid residues relating to catalytic function, random mutation of the undecaprenyl diphosphate synthase gene of Micrococcus luteus B-P 26 was carried out to construct a mutated gene library using an error-prone polymerase chain reaction. From the library, the mutants showing poor enzymatic activity were selected by the colony autoradiography method. Among 31 negative clones selected from 3,000 mutants, two clones were found to contain only one amino acid substitution at either Asn-77 or Trp-78. To determine the functional roles of these interesting residues, we prepared six mutated enzymes with substitutions at residues Asn-77 or Trp-78 by site-directed mutagenesis. Substitution of Asn-77 with Ala, Asp, or Gln resulted in a dramatic decrease in catalytic activity, but the K(m) values for both allylic and homoallylic substrates of these mutant enzymes were comparable to those of the wild-type. On the other hand, three Trp-78 mutants, W78I, W78R, and W78D, showed 5-20-fold increased K(m) values for farnesyl diphosphate but not for Z-geranylgeranyl diphosphate. However, these mutants showed moderate levels of enzymatic activity and comparable K(m) values for isopentenyl diphosphate to that of the wild-type. These results suggest that the Asn-Trp motif is involved in the binding of farnesyl diphosphate and enzymatic catalysis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
917-22
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Significance of Asn-77 and Trp-78 in the catalytic function of undecaprenyl diphosphate synthase of Micrococcus luteus B-P 26.
pubmed:affiliation
Institute for Chemical Reaction Science, Tohoku University, Katahira Aoba-ku, Sendai 980-8577, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't