UNUSUAL BRANCH POINT SELECTION IN PROCESSING OF HUMAN GROWTH-HORMONE PRE-MESSENGER RNA
UNUSUAL BRANCH POINT SELECTION IN PROCESSING OF HUMAN GROWTH-HORMONE PRE-MESSENGER RNA
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DOI：
10.1128/mcb.8.5.2011
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发表时间：
1988-05-01
影响因子：
5.3
通讯作者：
BARTA, A
中科院分区：
文献类型：
--
作者：
HARTMUTH, K;BARTA, A
人类生长激素基因的内含子A在3”剪接位点前的56个核苷酸内不含A残基。对切除的内含子的分析显示，在3”剪接位点上游28个核苷酸的C残基是主要的分支受体核苷酸。另外两个次要的支链核苷酸在-22和-36位被鉴定为U残基。在-22位的腺苷取代导致仅对该核苷酸形成旋链。因此，C和U残基可以有效地作为天然分支受体，但如果在适当的区域有A残基是首选的。此外，这些数据有力地强调了距离约束对水平井地层的重要性。为了解释分支受体核苷酸的选择，讨论了分支点序列与U2 RNA的潜在碱基配对相互作用。
Intron A of the human growth hormone gene does not contain an A residue within 56 nucleotides preceding the 3'' splice site. The analysis of the excised intron lariat revealed a C residue 28 nucleotides upstream from the 3'' splice site as the major branch acceptor nucleotide. Two additional minor branched nucleotides were identified as U residues at positions -22 and -36. An adenosine substitution at position -22 results in lariat formation solely to this nucleotide. Therefore, C and U residues can function efficiently as natural branch acceptors, but an A residue is preferred if available in the proper region. In addition, the data strongly reinforce the importance of the distance constraint for lariat formation. To explain selection of the branch acceptor nucleotide, potential base-pairing interactions of branch point sequences with the U2 RNA are discussed.