question: What are the exonic splice enhancers?
answer: In mammals there is a bias in amino acid usage near splice sites that is explained, in large part, by the high density of exonic splicing enhancers (ESEs) in these regions. Exonic splicing enhancers (ESEs) activate pre-mRNA splicing by promoting the use of the flanking splice sites. Some of these variants may have an effect on pre-mRNA splicing, either by altering degenerate positions of splice site sequences or by affecting intronic or exonic splicing regulatory sequences such as exonic splicing enhancers (ESEs). For inherited disease, the main mechanism responsible for the splicing defect is splice site loss, whereas for cancer the predominant mechanism of splicing disruption is predicted to be exon skipping via loss of exonic splicing enhancers or gain of exonic splicing silencer elements. FELINES was shown to be useful for characterizing branchsites, polypyrimidine tracts and 5' and 3' splice sites in the intron databases and exonic splicing enhancers (ESEs) in S.pombe exons. Unexpectedly, a fully experimental dataset identifies motifs that commonly behave opposite to the consensus, for example, being enriched in exon cores where splice-associated mutations are rare.Prior analyses that used the RESCUE-ESE set of hexamers captured the properties of consensus exonic splice enhancers.