Growth-rate-dependent regulation of 6-phosphogluconate dehydrogenase level mediated by an anti-Shine-Dalgarno sequence located within the Escherichia coli gnd structural gene.
Growth-rate-dependent regulation of 6-phosphogluconate dehydrogenase level mediated by an anti-Shine-Dalgarno sequence located within the Escherichia coli gnd structural gene.
复制标题
由位于大肠杆菌 gnd 结构基因内的抗 Shine-Dalgarno 序列介导的 6-磷酸葡萄糖酸脱氢酶水平的生长速率依赖性调节。
DOI：
10.1073/pnas.86.4.1138
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发表时间：
1989
影响因子：
11.1
通讯作者：
WolfJr,RE
中科院分区：
文献类型：
--
作者：
Carter-Muenchau,P;WolfJr,RE
先前的研究表明，在大肠杆菌 K-12 中，由 gnd 基因编码的 6-磷酸葡萄糖酸脱氢酶表达的生长速率依赖性调节发生在转录后水平，并由位于编码序列深处（密码子 48 和 118 之间）的负控制元件介导。对生长速率调节的 gnd-lacZ 翻译融合体的删除分析表明， gnd 元件是 gnd mRNA 密码子 67 和 78 之间的片段，与 gnd 核糖体结合位点的大部分互补，包括其 Shine-Dalgarno 序列。通过合成“内部互补序列”的克隆进一步定义了元件的边界。当核心内部互补序列元件放置在密码子 40 和密码子 69 之间的多个位点时，会实现生长速率依赖性调节，但当移动到密码子 13 时，它会严重降低基因表达。通过定点诱变引入元件的单突变和双突变的调节效果与各个 mRNA 折叠成隔离核糖体结合位点的二级结构的能力相关。因此，gnd 基因的内部调节元件似乎起到顺式反义 RNA 的作用。
Previous work has shown that in Escherichia coli K-12 growth-rate-dependent regulation of expression of 6-phosphogluconate dehydrogenase, encoded by the gnd gene, occurs at the posttranscriptional level and is mediated by a negative control element that lies deep in the coding sequence, somewhere between codons 48 and 118. Deletion analysis of a growth-rate-regulated gnd-lacZ translational fusion showed that the element is the segment of gnd mRNA between codons 67 and 78 that is complementary to an extensive portion of the gnd ribosome-binding site, including its Shine-Dalgarno sequence. The boundaries of the element were further defined by the cloning of a synthetic "internal complementary sequence." The core internal complementary sequence element effected growth-rate-dependent regulation when placed at several sites between codon 40 and codon 69, but it severely reduced gene expression when moved to codon 13. The effect on regulation of single and double mutations introduced into the element by site-directed mutagenesis correlated with the ability of the respective mRNAs to fold into secondary structures that sequester the ribosome-binding site. Thus the gnd gene's internal regulatory element appears to function as a cis-acting antisense RNA.