细菌基因中的广泛的偏差是由失控的转录驱动的
bioRxiv : the preprint server for biology
|September 5, 2025
概括
细菌的基因表达依赖于富含 purin 的序列来防止Rho因子过早的转录终止. 这种精氨酸偏好影响细菌的基因组进化和基因适应.
科学领域:
- 分子生物学
- 基因组学
- 细菌遗传学
背景情况:
- 细菌在它们的基因中表现出纯核酸 (腺素和关氨酸) 超过金酸 (细胞酸和胆氨酸).
- 在RNA聚合酶超越核糖体的脱离转录过程中, 新生RNA会受到Rho等终结因子的影响.
- 在细菌中调节基因表达的关键机制是Rho依赖终结.
研究的目的:
- 研究细菌转录中富含 purin 的基因序列的功能意义.
- 确定核酸组成在防止Rho过早转录终止方面的作用.
- 了解细菌基因组中的核酸偏差的进化影响.
主要方法:
- 在 Bacillus subtilis 中使用了大规模并行报告测试.
- 分析了Rho-依赖终结的要求,重点是核酸组成和歪曲.
- 在编码 (sense) 和非编码 (antisense) 序列中比较核酸含量.
主要成果:
- 高素对氨酸偏差和高胺含量有利于Rho依赖终结.
- 富含 purin 的编码序列避免过早终止,而富含 pyrimidine 的反意义序列则被杀.
- 这种机制解释了大多数转录失控的细菌中偏差的子使用,除了缺乏Rho的细菌.
结论:
- 通过防止Rho介导终结,对富含 purin的序列的偏好对于有效的基因表达至关重要.
- 避免过早的转录终止对细菌基因组进化造成了重大限制.
- 核酸含量偏差影响了外来基因在细菌基因组中的适应.
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