MOLECULAR-CLONING AND SEQUENCING OF AMA-1, THE GENE ENCODING THE LARGEST SUBUNIT OF CAENORHABDITIS-ELEGANS RNA POLYMERASE-II
MOLECULAR-CLONING AND SEQUENCING OF AMA-1, THE GENE ENCODING THE LARGEST SUBUNIT OF CAENORHABDITIS-ELEGANS RNA POLYMERASE-II
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DOI：
10.1128/mcb.9.10.4119
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发表时间：
1989-10-01
影响因子：
5.3
通讯作者：
RIDDLE, DL
中科院分区：
文献类型：
--
作者：
BIRD, DM;RIDDLE, DL
两个基因组序列，共享同源性RpII 215，基因编码的RNA聚合酶II在果蝇的最大亚基，已被分离出线虫线虫小杆线虫。这些序列之一被物理定位在IV号染色体上，位于从左缺陷断裂点缺失25个缺失酶（kb）的缺陷mDf 4的区域内。该位置对应于ama-1（对α-SMA的抗性）。鹅膏蕈碱），先前显示编码RNa聚合酶II的亚基的基因。北方（RNA）印迹和DNA测序显示ama-1跨越10 kb，被11个内含子打断，并编码5.9 kb的mRNA。分离cDNA克隆并部分测序以确认3“末端和几个剪接点。推断的1,859个残基的ama-1产品的分析表明相当大的身份与RNAP II的最大亚基从其他生物体，包括存在一个锌指基序附近的氨基末端，和一个羧基末端结构域的42个串联重复七聚体的共识Tyr Ser Pro Thr Ser Pro Ser。后一个结构域被发现是由四个外显子编码。此外，该序列相对于遗传图谱定向ama-1转录。所述第二光滑用果蝇探针检测到的elegans序列，命名为rpc-1，被发现编码一个4.8kb的转录本，并与编码酵母RNA聚合酶III最大亚基的基因强烈杂交，暗示rpc-1编码线虫中的类似肽。与ama-1相比，rpc-1没有被检测到的mDf 4或更大缺陷删除，表明这些基因不接近150 kb。ama-1侧翼的基因，包括两个胶原蛋白基因，也已经被鉴定出来。
Two genomic sequences that share homology with RpII215, the gene encoding the largest subunit of RNA polymerase II in Drosophila melanogaster, have been isolated from the nematode Caenorhabditis elegans. One of these sequences was physically mapped on chromosome IV within a region deleted by the deficiency mDf4, 25 kilobases (kb) from the left deficiency breakpoint. This position corresponds to ama-1 (resistance to .alpha.-amanitin), a gene shown previously to encode a subunit of RNa polymerase II. Northern (RNA) blotting and DNA sequencing revealed that ama-1 spans 10 kb, is punctuated by 11 introns, and encodes a 5.9-kb mRNA. A cDNA clone was isolated and partially sequenced to confirm the 3'' end and several splice junctions. Analysis of the inferred 1,859-residue ama-1 product showed considerable identity with the largest subunit of RNAP II from other organisms, including the presence of a zinc finger motif near the amino terminus, and a carboxyl-terminal domain of 42 tandemly reiterated heptamers with the consensus Tyr Ser Pro Thr Ser Pro Ser. The latter domain was found to be encoded by four exons. In addition, the sequence oriented ama-1 transcription with respect to the genetic map. The second C. elegans sequence detected with the Drosophila probe, named rpc-1, was found to encode a 4.8-kb transcript and hybridized strongly to the gene encoding the largest subunit of RNA polymerase III from yeast, implicating rpc-1 as encoding the analogous peptide in the nematode. By contrast with ama-1, rpc-1 was not deleted by mDf4 or larger deficiencies examined, indicating that these genes are no closer than 150 kb. Genes flanking ama-1, including two collagen genes, also have been identified.