脑心肌炎病毒多聚蛋白编码区起始与终止区的密码子使用模式

The Codon Usage Pattern for Translation Initiation and Termination Regions in the Whole Coding Sequence of Encephalomyocarditis Virus

文中利用特定区域密码子使用偏嗜性对数公式分析了脑心肌炎病毒(Encephalomyocarditis virus,EMCV)多聚蛋白编码基因的翻译起始区域与翻译终止区域的密码子使用模式。结果表明,EMCV多聚蛋白编码区内翻译起始序列区的同义密码子使用偏嗜性的正负偏差总体是平衡的,但几种在整体多聚蛋白质编码区域内使用为负偏嗜的稀有密码子却倾向于出现于编码起始区和终止区。这一有趣的现象,可利用"稀有密码子调控假说"来解释为EMCV开放阅读框两端的稀有密码子偏好性使用对整体阅读框的表达具有负调控作用。该研究说明"稀有密码子调控假说"不仅适用于细菌,而且也适用于一些RNA病毒基因组。

The codon usage pattern for the translational initiation and termination regions of encephalomyocarditis virus （ EMCV ） was particu- larly analyzed. The results indicate that the codon usage pattern with low propensity at some sites in the translation initiation and termination regions is preferentially existed, and the interesting phenomenon may imply a negative effect on gene expression, which can be explained by the ＂minor codon modulator hypothesis＂. Obviously, some information about the pattern of codon usage in the two target regions flanking the open reading frame of HCV may indicate that the codons with low-usage may have a more obvious effect on translation process. The proposed results imply that the ＂minor codon modulator hypothesis＂ may be applied to both bacteria and some RNA viruses （e. g. EMCV）.