Linked Life Data

9738902

Source:http://linkedlifedata.com/resource/pubmed/id/9738902

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-10-1
pubmed:databankReference
pubmed:abstractText
We have overexpressed the gene for dihydrofolate reductase (DHFR) from Thermotoga maritima in Escherichia coli and characterized the biochemical properties of the recombinant protein. This enzyme is involved in the de novo synthesis of deoxythymidine 5'-phosphate and is critical for cell growth. High levels of T. maritima DHFR in the new expression system conferred resistance to high levels of DHFR inhibitors which inhibit the growth of non-recombinant cells. The enzyme was purified to homogeneity in the following two steps: heat treatment followed by affinity chromatography or cation-exchange chromatography. Most of the biochemical properties of T. maritima DHFR resemble those of other bacterial or eukaryotic DHFRs, however, some are unique to T. maritima DHFR. The pH optima for activity, Km for substrates, and polypeptide chain length of T. maritima DHFR are similar to those of other DHFRs. In addition, the secondary structure of T. maritima DHFR, as measured by circular dichroism, is similar to that of other DHFRs. Interestingly, T. maritima DHFR exhibits some characteristics of eukaryotic DHFRs, such as a basic pI, an excess of positively charged residues in the polypeptide chain and activation of the enzyme by inorganic salts and urea. Unlike most other DHFRs which are monomeric or part of a bifunctional DHFR-thymidylate synthase (TS) enzyme, T. maritima DHFR seems to generally form a dimer in solution and is also much more thermostable than other DHFRs. It may be that dimer formation is a key factor in determining the stability of T. maritima DHFR.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
255
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
628-37
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Purification and characterization of recombinant Thermotoga maritima dihydrofolate reductase.
pubmed:affiliation
Research Institute CERIA-COOVI, Brussels, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't