The 3-methylcytidine (m 3 C) modification is widely found in eukaryotic species of tRNA Ser , tRNA Thr , and tRNA Arg ; at residue 32 in the anti-codon loop; and at residue e2 in the variable stem of tRNA Ser . Little is known about the function of this modification or about the specificity of the corresponding methyltransferase, since the gene has not been identified. We have used a primer extension assay to screen a battery of methyltransferase candidate knockout strains in the yeast Saccharomyces cerevisiae, and find that tRNA Thr(IGU) from abp140-D strains lacks m 3 C. Curiously, Abp140p is composed of a poorly conserved N-terminal ORF fused by a programed +1 frameshift in budding yeasts to a C-terminal ORF containing an S-adenosylmethionine (SAM) domain that is highly conserved among eukaryotes. We show that ABP140 is required for m 3 C modification of substrate tRNAs, since primer extension is similarly affected for all tRNA species expected to have m 3 C and since quantitative analysis shows explicitly that tRNA Thr(IGU) from an abp140-D strain lacks m 3 C. We also show that Abp140p (now named Trm140p) purified after expression in yeast or Escherichia coli has m 3 C methyltransferase activity, which is specific for tRNA Thr(IGU) and not tRNA Phe and occurs specifically at C 32 . We suggest that the C-terminal ORF of Trm140p is necessary and sufficient for activity in vivo and in vitro, based on analysis of constructs deleted for most or all of the N-terminal ORF. We also suggest that m 3 C has a role in translation, since trm140-D trm1-D strains (also lacking m 2,2 G 26 ) are sensitive to low concentrations of cycloheximide.
PCD was effective first-line treatment of complicated pyogenic liver abscesses, which often require catheter adjustment and salvage drainage procedures to reliably achieve success.
We found a highly significant association between increasing BMI and axillary LN dimensions independent of age and breast density with strong interobserver agreement. The increase in LN size was driven by expansion of the LN hilum secondary to fat infiltration. Advances in knowledge: This preliminary work determined a relationship between fat infiltrated axillary lymph nodes and obesity.
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