Structure and properties of a bovine liver UGA suppressor serine tRNA with a tryptophan anticodon |
| |
Authors: | Alan Diamond Bernard Dudock Dolph Hatfield |
| |
Affiliation: | Department of Biochemistry State University of New York Stony Brook, New York 11794, USA;Laboratory of Molecular Carcinogenesis National Cancer Institute Bethesda, Maryland 20205, USA |
| |
Abstract: | A bovine liver serine tRNA with a variety of unusual features has been sequenced and characterized. This tRNA is aminoacylated with serine, although it has a tryptophan anticodon CmCA. In ribosome binding assays, this tRNA (tRNACmCASer) binds to the termination codon UGA and shows little or no binding in response to a variety of other codons including those for tryptophan and serine. The unusual codon recognition properties of this molecule were confirmed in an in vitro assay where this tRNA suppressed UGA termination. This is the first naturally occurring eucaryotic suppressor tRNA to be so characterized. Other unusual features, possibly related to the ability of this tRNA to read UGA, are the presence of two extra nucleotides, compared to all other tRNAs, between the universal residues U at position 8 and A at position 14 and the presence of an extra unpaired nucleotide within the double-stranded loop IV stem. This tRNA is also the largest eucaryotic tRNA sequenced to date (90 nucleotides). Despite its size, however, it contains only six modified residues. tRNACmCASer shows extremely low homology to other mammalian serine (47–52% homology) or tryptophan (49% homology) tRNAs. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|