Effects of the trinucleotide preceding the self-cleavage site on eggplant latent viroid hammerheads: differences in co- and post-transcriptional self-cleavage may explain the lack of trinucleotide AUC in most natural hammerheads.
Effects of the trinucleotide preceding the self-cleavage site on eggplant latent viroid hammerheads: differences in co- and post-transcriptional self-cleavage may explain the lack of trinucleotide AUC in most natural hammerheads.
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在自切除位点之前的三核苷酸对茄子潜伏病毒锤的影响：转录后和后的自结论的差异可能解释了大多数天然锤头中缺乏三核苷酸AUC的差异。
DOI：
10.1093/nar/gkl717
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发表时间：
2006
影响因子：
14.9
通讯作者：
Gago, Selma
中科院分区：
文献类型：
--
作者：
Carbonell, Alberto;De la Pena, Marcos;Flores, Ricardo;Gago, Selma
茄子潜伏类病毒（ELVd）在其（+）和（-）链上可形成稳定的锤头状结构。这些核酶具有我在天然锤头中报道的最长螺旋，其中ELVd（+）锤头的螺旋特别稳定（5/7 bp为G-C）。此外，这个锤头鲨的自我切割位点之前的三核苷酸是AUA，它与在一些天然锤头鲨中也发现的GUA一起，偏离了大多数天然锤头鲨（包括ELVd（−）锤头鲨）中存在的GUC。当ELVd（+）锤头的自切割位点之前的AUA三核苷酸被GUA和GUC以及AUC（天然锤头中基本上不存在）取代时，纯化锤头在低镁下的自切割速率常数的值为：ELVd-（+）-AUC> ELVd-（+）-GUC> ELVd-（+）-GUA> ELVd-（+）-AUA。然而，ELVd-（+）-AUC锤头在体外转录过程中催化效率较低，最有可能是因为瞬时采用无催化活性的亚稳结构。这些结果表明，天然锤头已进化选择共转录功能，并提供了一个模型，解释缺乏三核苷酸AUC之前的自我切割位点的大多数天然锤头。与其他天然锤头的比较显示，ELVd-（+）-GUC和ELVd-（+）-AUC锤头在具有低镁的转录后环境中具有最高的催化活性。
Eggplant latent viroid (ELVd) can form stable hammerhead structures in its (+) and (−) strands. These ribozymes have the longest helices I reported in natural hammerheads, with that of the ELVd (+) hammerhead being particularly stable (5/7 bp are G-C). Moreover, the trinucleotide preceding the self-cleavage site of this hammerhead is AUA, which together with GUA also found in some natural hammerheads, deviate from the GUC present in most natural hammerheads including the ELVd (−) hammerhead. When the AUA trinucleotide preceding the self-cleavage site of the ELVd (+) hammerhead was substituted by GUA and GUC, as well as by AUC (essentially absent in natural hammerheads), the values of the self-cleavage rate constants at low magnesium of the purified hammerheads were: ELVd-(+)-AUC≈ELVd-(+)-GUC>ELVd-(+)-GUA> ELVd-(+)-AUA. However, the ELVd-(+)-AUC hammerhead was the catalytically less efficient during in vitro transcription, most likely because of the transient adoption of catalytically-inactive metastable structures. These results suggest that natural hammerheads have been evolutionary selected to function co-transcriptionally, and provide a model explaining the lack of trinucleotide AUC preceding the self-cleavage site of most natural hammerheads. Comparisons with other natural hammerheads showed that the ELVd-(+)-GUC and ELVd-(+)-AUC hammerheads are the catalytically most active in a post-transcriptional context with low magnesium.
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DOI：
10.1073/pnas.89.9.3711
发表时间：
1992-05-01
影响因子：
11.1
作者：
HERNANDEZ, C;FLORES, R
通讯作者：
FLORES, R
DOI：
10.1073/pnas.91.15.6977
发表时间：
1994-07-19
影响因子：
11.1
作者：
LONG, DM;UHLENBECK, OC
通讯作者：
UHLENBECK, OC
影响因子：
14.9
作者：
MILLER, WA;SILVER, SL
通讯作者：
SILVER, SL
影响因子：
3.7
作者：
MILLER, WA;HERCUS, T;GERLACH, WL
通讯作者：
GERLACH, WL
DOI：
10.1073/pnas.94.21.11262
发表时间：
1997-10-14
影响因子：
11.1
作者：
Navarro, B;Flores, R
通讯作者：
Flores, R