These protein-coding sequences make up 1-2% of the human genome.
These signs can be broadly categorized as either signals, specific sequences that indicate the presence of a gene nearby, or content, statistical properties of protein-coding sequence itself.
The results consisted of all sequences that contain a nuclear protein-coding sequence available for that taxon at the time of the query.
The most challenging case was that of the arbuscular mycorrhizal fungi, for which very few protein-coding sequences are available.
They concluded that the behavior applies better to non-coding than to protein-coding sequences and suggested that non-coding DNA resembles a natural language.
Evolutionary change may occur both through changes in protein-coding sequences and through sequence changes that alter gene regulation".
In addition, bias may arise due to differentials in the amount of protein-coding sequence on each strand, as codons do not all occur with equal frequency.
Together these results suggest that there is a large class of functional protein-coding sequences evolving under weak selective constraint in the Drosophila genome [ 34].
Excluding protein-coding sequences, introns, and regulatory regions, much of the non-coding DNA is composed of:
The majority of genetic variants that underlie mendelian disorders disrupt protein-coding sequences.
