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Support Vector Machines and Kernels for Computational Biology

Figure 4

The major steps in protein synthesis: transcription, post-processing, and translation.

In the post-processing step, the pre-mRNA is transformed into mRNA. One necessary step in the process of obtaining mature mRNA is called splicing. The mRNA sequence of a eukaryotic gene is “interrupted” by noncoding regions called introns. A gene starts with an exon and may then be interrupted by an intron, followed by another exon, intron, and so on until it ends in an exon. In the splicing process, the introns are removed. There are two different splice sites: the exon–intron boundary, referred to as the donor site or 5′ site (of the intron), and the intron–exon boundary, that is, the acceptor or 3′ site. Splice sites have quite strong consensus sequences, i.e., almost every position in a small window around the splice site is representative of the most frequently occurring nucleotide when many existing sequences are compared in an alignment (cf. Figure 5). (The caption text appeared similarly in [30], the idea for this figure is from [11].)

Figure 4