一个活性-抵抗权衡限制了酶进化的进化
bioRxiv : the preprint server for biology
|February 6, 2026
概括
产生抗生素的真菌通过与酶效率的权衡,对酸 (MPA) 进化了自我抵抗力. 对利巴维林-5'-单酸盐 (RVP) 已经存在的耐药性可能为MPA耐药性铺平了道路.
科学领域:
- 生物化学 生物化学
- 进化生物学 进化生物学
- 遗传学 是一个遗传学.
背景情况:
- 抗生素生产者必须具备自我抵抗机制,以生存自己的毒素.
- 抗生素自我抵抗的进化起源,特别是在抗生素生产之前,仍然不太清楚.
- 菌酸 (MPA) 是一种由真菌产生的抗生素,可以抑制因氨酸单酸脱酶 (IMPDH).
研究的目的:
- 调查抗生素生产生物体对MPA自身抗性的进化起源.
- 了解MPA电阻与IMPDH的催化效率之间的关系.
- 探索其他IMPDH抑制剂在MPA耐药性演变中的作用.
主要方法:
- 对IMPDH-B基因和真菌物种的遗传学分析.
- 现存和复活的祖先IMPDH酶的表征.
- 酶活性测定用于评估MPA和利巴维林-5 extquotesingle-monophosphate (RVP) 的耐药性和催化效率.
主要成果:
- IMPDH-B中的MPA耐药性在祖先酶Anc2和Anc3之间演变,与催化效率的显著损失相吻合.
- 在所有测试的酶中观察到MPA耐药性和酶活性之间的持续性权衡.
- 现存的和祖先的IMPDH-B都对RVP表现出耐药性,而RVP耐药性可能先于MPA耐药性.
结论:
- 菌中MPA耐药性的演变受到IMPDH催化效率的权衡的约束.
- 对RVP的先前存在的耐药性可能为MPA耐药性的后续发展创造了允许的进化背景.
- 横向基因转移事件可能在IMPDH-B基因在真菌系的分布中发挥了重要作用.
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