The marginal importance of tRNA positions for identifying the corresponding amino acid of tRNAs, measured by Cramer's V. Shown is the level of marginal information embedded in 43 tRNA positions for each of the 20 amino acids. A gradient of light blue to dark purple colors indicates the predicting power of a position for distinguishing the identity of a specific amino acid (from other amino acids). For example, positions N1 and N72 may be used to discern tRNAs for Tyr from tRNAs of other amino acids. tRNAs for Gln also use these positions, but they do not offer a perfect separation from tRNAs for other amino acids (therefore are not colored in dark red). In contrast, other tRNAs, such as the tRNAs for Val, have only light blue positions, indicating that no single position can be used to discern between tRNAs for Val and tRNAs for other amino acids.
