The phrase "a random usage" is correct and usable in written English.
It can be used to describe an instance or example of something being used without any specific pattern or intention.
Example: "The author included a random usage of slang that surprised many readers."
Alternatives: "an arbitrary use" or "a haphazard application".
Annotated smORFs display a lower than random usage of arginine, which is a hallmark of translated proteins (King and Jukes, 1969).
Nc (or ENC) is analogous to the effective number of alleles at a locus and ranges from 61 (random usage) to 20 (one codon per amino acid).
A high MI value means not random usage of the corresponding codon among genes that are expressed in the same tissue.
Similarly, a measure of the extent that synonymous codons depart from random usage (computed as relative synonymous codon usage values) showed a conserved pattern in both strands, evidencing the high prevalence of A or T nucleotides at third codon positions.
Animal mitochondrial genomes sometimes deviate from a random nucleotide usage, which may be due to the directional mutation pressure and the non-asymmetrical base composition of both the strands [ 13].
Genes display a non-random usage of synonymous codons and a measure of this non-randomness is RSCU (Relative synonymous codon usage).
Briefly, the RSCU of a codon (X) represents the number of times it appears in a sequence (observed usage), divided by the expected usage value, assuming random usage of synonymous codons for the corresponding amino acid (C).
If all codons for each amino acid are used equally (completely random usage), ENC will be 61; the other extreme would be if a single codon is used for each amino acid yielding an ENC of 20.
DOI: http://dx.doi.org/10.7554/eLife.03528.016 As a further indicator of smORF translation, we studied the amino acid composition of translated smORFs, compared to canonical long proteins and expected random usage.
In fact, RSS heterogeneity is a major reason for non-random usage in V(D J recombination.
