Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1975-11-8
pubmed:abstractText
Isoleucyl-tRNA formation catalysed by isoleucine: tRNA ligase is stimulated by both Mg2+ and spermine in the pH-range 7.0 to 8.0 at 310 K. At low [Mg2+] the acceleration caused by both cations together exceeds the sum of their individual effects. 2. The spermine-stimulated reaction has a steeper temperature-dependence than reaction in the presence of Mg2+. Two phases in the kinetics of isoleucyl-tRNA formation are detected in the presence of Mg2+ plus or minus spermine, but only a single step is observed in the presence of spermine alone. Thus the rate-limiting steps under normal assay conditions are different for the two cations. 3. Enzyme-bound isoleucyl-AMP can be formed in the absence of Mg-2+ and plus or minus spermine. 4. It is concluded that there is no evidence for cation-dependent differences in the reaction mechanism of isoleucine: tRNA ligase, though there are certainly differences in the relative rates of some of the individual steps.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
169-73
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
The effects of spermine and Mg2+ on the catalytic mechanism of isoleucine: tRNA ligase.
pubmed:publicationType
Journal Article