CRISPR families of the crenarchaeal genus Sulfolobus: bidirectional transcription and dynamic properties
CRISPR families of the crenarchaeal genus Sulfolobus: bidirectional transcription and dynamic properties
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DOI：
10.1111/j.1365-2958.2009.06641.x
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发表时间：
2009-04-01
影响因子：
3.6
通讯作者：
Garrett, Roger A.
中科院分区：
文献类型：
--
作者：
Lillestol, Reidun K.;Shah, Shiraz A.;Garrett, Roger A.
基于其重复，领导区域，相关的CAS基因以及对病毒和质粒的推定识别序列，磺胺bo子的定期间隔短的短质体重复序列（CRISPR）属于三个主要家庭。间隔序列与磺胺盐的不同病毒和质粒相匹配，揭示了一些偏见，尤其是对家族III CRISPR的偏见。转录发生在磺胺酸的五个重复簇的两条链上，以及偶联质粒PKEF9的重复簇。 Leader Strand转录本涵盖了整个重复簇，并主要从3'-End进行处理，在重复序列内产生异质40-45 NT间隔RNA。 PKEF9领导者转录本的处理部分发生在间隔者中，并且不完整，可能反映了宿主酶的重复识别有缺陷。每个染色体重复簇的互补链产生了类似水平的转录本，并处理它们以产生类似于55 NT间隔RNA的离散。对磺胺溶液菌株P1和P2的部分相同重复簇的分析表明，仅当领导者和某些CAS基因链接时，间隔单元才会在上游添加到上游。重复群体的下游末端是保守的，因此缺失和重组事件在内部发生。
Clusters of regularly interspaced short palindromic repeats (CRISPRs) of Sulfolobus fall into three main families based on their repeats, leader regions, associated cas genes and putative recognition sequences on viruses and plasmids. Spacer sequence matches to different viruses and plasmids of the Sulfolobales revealed some bias particularly for family III CRISPRs. Transcription occurs on both strands of the five repeat-clusters of Sulfolobus acidocaldarius and a repeat-cluster of the conjugative plasmid pKEF9. Leader strand transcripts cover whole repeat-clusters and are processed mainly from the 3'-end, within repeats, yielding heterogeneous 40-45 nt spacer RNAs. Processing of the pKEF9 leader transcript occurred partially in spacers, and was incomplete, probably reflecting defective repeat recognition by host enzymes. A similar level of transcripts was generated from complementary strands of each chromosomal repeat-cluster and they were processed to yield discrete similar to 55 nt spacer RNAs. Analysis of the partially identical repeat-clusters of Sulfolobus solfataricus strains P1 and P2 revealed that spacer-repeat units are added upstream only when a leader and certain cas genes are linked. Downstream ends of the repeat-clusters are conserved such that deletions and recombination events occur internally.