BACTERIAL PEPTIDE-CHAIN RELEASE FACTORS - CONSERVED PRIMARY STRUCTURE AND POSSIBLE FRAMESHIFT REGULATION OF RELEASE FACTOR-II
BACTERIAL PEPTIDE-CHAIN RELEASE FACTORS - CONSERVED PRIMARY STRUCTURE AND POSSIBLE FRAMESHIFT REGULATION OF RELEASE FACTOR-II
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DOI：
10.1073/pnas.82.11.3616
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发表时间：
1985-01-01
影响因子：
11.1
通讯作者：
CASKEY, CT
中科院分区：
文献类型：
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作者：
CRAIGEN, WJ;COOK, RG;CASKEY, CT
大肠杆菌肽链释放因子是响应于特定的肽链终止密码子而指导翻译终止的蛋白质。密码子识别和肽基-tRNA水解的机制尚不清楚。对释放因子1（RF-1）和释放因子2（RF-2）的编码基因进行了表征，以研究蛋白质的结构-功能关系及其在细菌中的调控。本文报道了RF-1和RF-2的基因结构和RF-2的部分肽段序列，RF-1和RF-2在一级结构上高度同源。此外，框内过早蛋白石（UGA）终止密码子位于RF-2编码区内的氨基酸位置26。通过自动Edman降解对蛋白质的该区域进行测序以确认预测的阅读范围，并且鉴定RF-2基因的第二个独立分离物并测序以确认DNA序列。移码显然发生在提前终止密码子之前，因此允许RF-2的翻译完成。这可能代表RF-2表达的翻译控制机制。另一种可能的翻译调控手段进行了讨论。
Escherichia coli peptide chain release factors are proteins that direct the termination of translation in response to specific peptide chain termination codons. The mechanisms of codon recognition and peptidyl-tRNA hydrolysis are unknown. The genes encoding release factor 1 (RF-1) and release factor 2 (RF-2) were characterized to study the structure-function relationships of the proteins and their regulation in the bacterium. The gene structure of RF-1 and RF-2, and a partial peptide sequence of RF-2 are presented, RF-1 and RF-2 are highly homologous in their primary structure. In addition, an in-frame premature opal (UGA) termination codon is located within the RF-2 coding region at amino acid position 26. This region of the protein was sequenced by automated Edman degradation to confirm the predicted reading fame, and a 2nd independent isolate of the RF-2 gene was identified and sequenced to confirm the DNA sequence. A frameshift apparently occurs prior to the premature termination codon, thus allowing for translation of RF-2 to be completed. This may represent a mechanism of translational control of RF-2 expression. An alternative possible means of translational regulation is discussed.