Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0039483 (
giant cell arteritis
)
3,204
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In many organisms, the UGA stop codon is recoded to insert selenocysteine (Sec) into proteins. Sec incorporation in bacteria is directed by an mRNA element, known as the Sec-insertion sequence (SECIS), located downstream of the Sec codon. Unlike other aminoacyl-tRNAs, Sec-tRNA
Sec
is delivered to the ribosome by a dedicated elongation factor, SelB. We recently identified a series of tRNA
Sec
-like tRNA genes distributed across Bacteria that also encode a canonical tRNA
Sec
. These tRNAs contain sequence elements generally recognized by cysteinyl-tRNA synthetase (CysRS). While some of these tRNAs contain a
UCA
Sec anticodon, most have a
GCA
Cys anticodon. tRNA
Sec
with
GCA
anticodons are known to recode UGA codons. Here we investigate the clostridial Desulfotomaculum nigrificans tRNA
Sec
-like tRNA
Cys
, and show that this tRNA is acylated by CysRS, recognized by SelB, and capable of UGA recoding with Cys in Escherichia coli. We named this non-canonical group of tRNA
Cys
as 'tRNA
ReC
' (Recoding with Cys). We performed a comprehensive survey of tRNA
ReC
genes to establish their phylogenetic distribution, and found that, in a particular lineage of clostridial Pelotomaculum, the Cys identity elements of tRNA
ReC
had mutated. This novel tRNA, which contains a
UCA
anticodon, is capable of Sec incorporation in E. coli, albeit with lower efficiency relative to Pelotomaculum tRNA
Sec
. We renamed this unusual tRNA
Sec
derived from tRNA
ReC
as 'tRNA
ReU
' (Recoding with Sec). Together, our results suggest that tRNA
ReC
and tRNA
ReU
may serve as safeguards in the production of selenoproteins and - to our knowledge - they provide the first example of programmed codon-anticodon mispairing in bacteria.
...
PMID:Recoding of the selenocysteine UGA codon by cysteine in the presence of a non-canonical tRNA
Cys
and elongation factor SelB. 2987 65
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