SPLICING SIGNALS IN DROSOPHILA - INTRON SIZE, INFORMATION-CONTENT, AND CONSENSUS SEQUENCES
SPLICING SIGNALS IN DROSOPHILA - INTRON SIZE, INFORMATION-CONTENT, AND CONSENSUS SEQUENCES
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DOI：
10.1093/nar/20.16.4255
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发表时间：
1992-08-25
影响因子：
14.9
通讯作者：
FIELDS, C
中科院分区：
文献类型：
--
作者：
MOUNT, SM;BURKS, C;FIELDS, C
从Genbank（发布号64.0）中提取了209个果蝇内含子数据库，并通过多种方法进行了检查，以表征可能作为信使RNA剪接信号的特征。观察到大小分布紧密：数据库中最小的内含子有51个核苷酸，超过一半的内含子长度小于80个核苷酸，其中大多数长度在59 - 67个核苷酸之间。在大内含子和小内含子中发现的果蝇剪接位点彼此之间以及在脊椎动物内含子中发现的剪接位点之间只有细微的差别。然而，较大的内含子在3'剪接位点上游11到21个核苷酸之间的区域具有更高的嘧啶丰富度。果蝇的分支点一致矩阵类似于C T A A T（分支形成发生在下划线的A处），并且与相应的哺乳动物信号不同，在分支点之前的位置没有G。该序列的出现分布表明，5‘剪接位点与分支点之间的最小距离约为38个核苷酸，3’剪接位点与分支点之间的最小距离为15个核苷酸。我们使用的方法除了在剪接位点附近的几个核苷酸中检测到外显子序列的信息外，没有检测到其他信息。然而，果蝇与许多其他物种相似，在富含a + T的外显子和内含子之间存在a + T含量的不连续。
A database of 209 Drosophila introns was extracted from Genbank (release number 64.0) and examined by a number of methods in order to characterize features that might serve as signals for messenger RNA splicing A tight distribution of sizes was observed: while the smallest introns in the database are 51 nucleotides more than half are less than 80 nucleotides in length and most of these have lengths in the range of 59 - 67 nucleotides. Drosophila splice sites found in large and small introns differ in only minor ways from each other and from those found in vertebrate introns. However, larger introns have greater pyrimidine-richness in the region between 11 and 21 nucleotides upstream of 3' splice sites. The Drosophila branchpoint consensus matrix resembles C T A A T (in which branch formation occurs at the underlined A), and differs from the corresponding mammalian signal in the absence of G at the position immediately preceding the branchpoint The distribution of occurrences of this sequence suggests a minimum distance between 5' splice sites and branchpoints of about 38 nucleotides, and a minimum distance between 3' splice sites and branchpoints of 15 nucleotides. The methods we have used detect no information in exon sequences other than in the few nucleotides immediately adjacent to the splice sites. However, Drosophila resembles many other species in that there is a discontinuity in A + T content between exons and introns, which are A + T rich.