Are tRNA codes, tRNA synthetase code and amino acid popularity in proteins statistically related?

[SStell]

I am interested in knowing IF there is any statistical correlation between the number of tRNA code COPIES for each type, the number of tRNA synthetase code copies for each type and the abundance of each amino acid found in humans. Or is there any hard data that you could steer me to on this?

 

For example:

 

7 copies of tRNA alanine, 7 copies of tRNA synthetase alanine, alanine occupies 3% of amino acids found in human proteins

[CharonY]

I think you may be misunderstanding a few things here. First, there is codon bias. That means that not all codon variants for a given amino acid are used at the same frequency. You may want to check wikipedia or some other common resource for a short overview.

Then, the abundance of a tRNA with a given anticodon does also vary, but in a much more dynamic way. A simple situation is if a certain amino acid is lacking, of course. But even for a given amino acid the various tRNAs carrying it vary in abundance. The regulation of these pathways can be rather complex. Typically (but not always), there is a correlation between tRNA abundance and the particular codon usage. The result is that genes using these high-abundant codons can be translated faster than if other codons are used. This is typically the case for genes that can become rate-limiting growth in unicellular organisms. Also note that codon bias and aa usage can vary significantly between organisms. Most of our knowledge is derived from model bacteria, yeast, and Drosophila but especially in more exotic bacteria things can be markedly different.

 

On top of it the number of tRNA genes also varies, allowing for further regulatory control of translation rates and aa usage. And even more control can be exerted via the tRNA synthetase activity. But I think the regulatory circuits are quite an advanced topic and there are still gaps in our understanding of the underlying regulation. Suffice to say that a simple 1 on 1 interpretation as outlined does not reflect the actual mechanism.

Edited October 20, 2015 by CharonY