Construction of anti-codon table of the plant kingdom and evolution of tRNA selenocysteine (tRNASec)

Abstract

AbstractBackgroundThe tRNAs act as a bridge between the coding mRNA and incoming amino acids during protein translation. The anti-codon of tRNA recognizes the codon of the mRNA and deliver the amino acid into the protein translation chain. However, we did not know about the exact abundance of anti-codons in the genome and whether the frequency of abundance remains same across the plant lineage or not.ResultsTherefore, we analysed the tRNAnome of 128 plant species and reported an anti-codon table of the plant kingdom. We found that CAU anti-codon of tRNAMethas highest (5.039%) whereas GCG anti-codon of tRNAArghas lowest (0.004%) abundance. However, when we compared the anti-codon frequencies according to the tRNA isotypes, we found tRNALeu(7.808%) has highest abundance followed by tRNASer(7.668%) and tRNAGly(7.523%). Similarly, suppressor tRNA (0.036%) has lowest abundance followed by tRNASec(0.066%) and tRNAHis(2.109). The genome ofIpomoea nil, Papaver somniferum, andZea maysencoded the highest number of anti-codons (isoacceptor) at 59 each whereas the genome ofOstreococcus tauriwas found to encode only 18 isoacceptors. ThetRNASecgenes undergone losses more frequently than duplication and we found thattRNASecshowed anti-codon switch during the course of evolution.ConclusionThe anti-codon table of the plant tRNA will enable us to understand the synonymous codon usage of the plant kingdom and can be very helpful to understand which codon is preferred over other during the translation.