Fichant G A
Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, NM 87545.
Hum Mol Genet. 1992 Jul;1(4):259-67. doi: 10.1093/hmg/1.4.259.
The exon positions located at the 5' and 3' splice sites are involved in two functions: in the accurate removal of introns from the nuclear pre-messenger RNAs and in coding for amino acids. Therefore, at least two constraints will act on the exon positions: the splicing constraint and the protein constraint. In the present study we investigate the effect of those constraints on a set of splice sites extracted from GenBank. The consensus matrices computed for each intron location in the reading frame present striking differences at the exon positions of the 5' splice sites. The results obtained can not be explained by the action of a single constraint but rather by the competition between the splicing and protein constraints. Out of eight sites corresponding to codons located in the vicinity of the intron, three present an amino acid distribution that differs greatly from the average amino acid composition of the proteins. Each of these three sites can be characterized by specific amino acids. Results show that the splicing constraint has an effect on the local amino acid composition of the protein as long as the function of the protein is not disrupted.
位于5'和3'剪接位点的外显子位置涉及两种功能：准确地从核内前体信使RNA中去除内含子以及编码氨基酸。因此，至少有两种限制作用于外显子位置：剪接限制和蛋白质限制。在本研究中，我们研究了这些限制对从GenBank中提取的一组剪接位点的影响。针对阅读框中每个内含子位置计算的共有矩阵在5'剪接位点的外显子位置呈现出显著差异。所获得的结果不能用单一限制的作用来解释，而应由剪接和蛋白质限制之间的竞争来解释。在与位于内含子附近的密码子相对应的八个位点中，有三个位点的氨基酸分布与蛋白质的平均氨基酸组成有很大差异。这三个位点中的每一个都可以由特定的氨基酸来表征。结果表明，只要蛋白质的功能不被破坏，剪接限制就会对蛋白质的局部氨基酸组成产生影响。
