在酶招募期间的基因共享揭示了不同的适应策略,包括大规模,持续的重复,没有分歧
bioRxiv : the preprint server for biology
|February 12, 2026
概括
有机体为新功能招募杂交的酶,平衡原始和新角色. 大肠杆菌的适应性进化表明,N-乙-D-曼诺胺激酶 (NanK) 被招募用于糖解,尽管保持其原始功能的压力.
科学领域:
- 进化生物学 进化生物学
- 生物化学 生物化学
- 微生物遗传学 微生物遗传学
背景情况:
- 酶可以重新用于新的代谢反应,这一过程对于生物体的适应至关重要.
- 酶招募需要平衡原始和新功能以保持健康.
- 创新-扩大-分歧模型解释了多功能酶如何通过基因重复和突变演变为专门的酶.
研究的目的:
- 研究在选择性压力下使用适应性进化在缺乏葡萄糖酶的 * Escherichia coli * 模型中的酶招募机制.
- 了解当它必须在获得新功能时保持其原始功能时,如何招募首选的酶候选者 (NanK).
主要方法:
- 适应性实验室进化缺乏葡萄糖酶的大肠杆菌,与四个杂交的酶代用物,包括NanK.
- 用全基因组测序分析*nanK*基因中的基因放大事件和非同义突变.
- 对原始 (N-乙-D-曼诺胺酶) 和新型 (葡萄酶) 功能的酶活性评估.
主要成果:
- 纳克通过两种不同的机制被招募来恢复糖解:基因放大随后发生突变,或广泛的片段放大 (最多127个副本).
- 这些招募策略在很大程度上保留了NanK的原生N-乙-D-曼诺胺激酶活性.
- 大规模的基因放大 (数百个副本) 抑制了序列分歧,挑战了标准的创新-放大-分歧模型.
结论:
- 基因共享可以影响进化轨迹,但可能不会阻止首选的乱交酶的招募,即使在功能约束下.
- 创新-放大-分歧模型可能通过适度的基因放大来促进,而通过大规模的放大来阻碍.
- 通过基因复制和分歧的进化创新对基因拷贝数量增加的程度敏感.
相关概念视频
Gene Duplication and Divergence
8.0K
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are...
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are...
8.0K
Genome Size and the Evolution of New Genes
9.2K
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
9.2K
Sustainable Development
15.2K
As the human population continues to grow and use resources, we must be mindful of our planet’s natural limits. Sustainable development provides a pathway to maintain and improve human life now while also ensuring that future generations will have the resources that they need. The long-term success of sustainability efforts rests on understanding the interplay between human actions and ecological systems.
15.2K
Enzymes
95.3K
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
95.3K
Centrosome Duplication
5.0K
The primary microtubule organizing center (MTOC) in animal cells is the centrosome. A centrosome has two cylindrical centrioles at its core. Each centriole consists of nine sets of three microtubules held together by proteins. The centrioles are positioned at right angles to each other and surrounded by a shapeless protein cloud called the pericentriolar matrix, or pericentriolar material (PCM).
To ensure that each daughter cell receives a centrosome after cell division, centrosome duplication...
To ensure that each daughter cell receives a centrosome after cell division, centrosome duplication...
5.0K
Divergence and Curl
3.3K
The divergence of a vector field at a point is the net outward flow of the flux out of a small volume through a closed surface enclosing the volume, as the volume tends to zero. More practically, divergence measures how much a vector field spreads out or diverges from a given point. For an outgoing flux, conventionally, the divergence is positive. The diverging point is often called the "source" of the field. Meanwhile, the negative divergence of a vector field at a point means that the vector...
3.3K


