A near-upstream element in a plant polyadenylation signal consists of more than six nucleotides
✍ Scribed by Qingshun Li; Arthur G. Hunt
- Book ID
- 104619705
- Publisher
- Springer
- Year
- 1995
- Tongue
- English
- Weight
- 794 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0167-4412
No coin nor oath required. For personal study only.
✦ Synopsis
A plant polyadenylation signal consists of three distinct components: a far-upstream element (FUE) that can control utilization of several polyadenylation sites, one or more near-upstream elements (NUEs) that control utilization of each site in a transcription unit, and polyadenylation site (CSs) themselves. NUEs have previously been suggested to be related to the mammalian polyadenylation signal AAUAAA. However, many plant genes do not contain AAUAAA-Iike motifs near their polyadenylation sites. To better understand the nature of NUEs, we conducted a systematic analysis of the N U E for one polyadenylation site (site 1) in the pea rbcS-E9 gene; this N U E lacks an AAUAAA motif. Linker substitution studies showed that the N U E for site 1 in this gene resides in the sequence AAAUGGAAA. Single-nucleotide substitutions in this domain had modest effects on the functioning of this NUE. Replacement of part of this sequence with the sequence AAUAAA increased the efficiency of this NUE. However, alteration of nucleotides immediately 3' of the AAUAAA reversed this effect. Our results indicate that the N U E for site 1 consists of as many as 9 nucleotides, that these 9 bases do not include an element that is intolerant of single base changes, that the sequence AAUAAA can function as a N U E for site 1, and that sequences flanking AAUAAA can affect the efficiency of functioning as a NUE.