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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1975-11-8
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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.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Isoleucine,
http://linkedlifedata.com/resource/pubmed/chemical/Ligases,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Transfer,
http://linkedlifedata.com/resource/pubmed/chemical/Spermine
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pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
54
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
169-73
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pubmed:dateRevised |
2007-7-23
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pubmed:meshHeading |
pubmed-meshheading:238842-Enzyme Activation,
pubmed-meshheading:238842-Escherichia coli,
pubmed-meshheading:238842-Hydrogen-Ion Concentration,
pubmed-meshheading:238842-Isoleucine,
pubmed-meshheading:238842-Kinetics,
pubmed-meshheading:238842-Ligases,
pubmed-meshheading:238842-Magnesium,
pubmed-meshheading:238842-RNA, Transfer,
pubmed-meshheading:238842-Spermine,
pubmed-meshheading:238842-Temperature
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pubmed:year |
1975
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pubmed:articleTitle |
The effects of spermine and Mg2+ on the catalytic mechanism of isoleucine: tRNA ligase.
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pubmed:publicationType |
Journal Article
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