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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2002-8-20
pubmed:abstractText
Leucyl-tRNA synthetase (LeuRS), one of the class Ia aminoacyl-tRNA synthetases, joins Leu to tRNA(Leu) and excludes noncognate amino acids in protein synthesis. In this study, Escherichia coli LeuRS mutants at amino acid E292, which was located in the connective polypeptide 1 insertion region, were synthesized. Although mutated LeuRS showed little change in structure compared with wild-type LeuRS, the mutants were impaired in activity to varying extents. It was also showed that mutations did not affect the adenylation reaction. However, mutated LeuRS can mischarge tRNA(Leu) isoacceptors tRN or tRN with isoleucine to different extents. Isoleucylation of tRN was more than that of tRN. The mutant LeuRS-E292S, which was picked out as an example for the investigation of the relationship between tRNA(Leu) isoacceptors and editing function, can discriminate the Watson-Crick base pair of the first base pair of tRNA(Leu) from the wobble base pair. The tRNA(Leu) with the Watson-Crick base pair may result in more isoleucylated product than that with the wobble base pair. The same phenomenon happened to another mutant, LeuRS-A293D. It seems that the flexibility of the first base pair affects the editing reaction of LeuRS. The results indicate that the flexibility of the first base pair of tRNA(Leu) may probably affect the mischarged 3'-end of tRNA(Leu) shuttling from synthetic site to editing site and that the transferred acceptor arm of tRNA(Leu) may interact with LeuRS in the region around E292.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10623-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:12186547-Acylation, pubmed-meshheading:12186547-Amino Acid Sequence, pubmed-meshheading:12186547-Amino Acid Substitution, pubmed-meshheading:12186547-Base Sequence, pubmed-meshheading:12186547-Circular Dichroism, pubmed-meshheading:12186547-Escherichia coli, pubmed-meshheading:12186547-Isoleucine, pubmed-meshheading:12186547-Kinetics, pubmed-meshheading:12186547-Leucine, pubmed-meshheading:12186547-Leucine-tRNA Ligase, pubmed-meshheading:12186547-Molecular Sequence Data, pubmed-meshheading:12186547-Nucleic Acid Conformation, pubmed-meshheading:12186547-RNA, Transfer, Amino Acyl, pubmed-meshheading:12186547-RNA Editing, pubmed-meshheading:12186547-Sequence Homology, Amino Acid, pubmed-meshheading:12186547-Spectrometry, Fluorescence, pubmed-meshheading:12186547-Structure-Activity Relationship, pubmed-meshheading:12186547-Substrate Specificity
pubmed:year
2002
pubmed:articleTitle
Discrimination of tRNA(Leu) isoacceptors by the mutants of Escherichia coli leucyl-tRNA synthetase in editing.
pubmed:affiliation
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, Shanghai 200031, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't