细菌中的血清酶同类菌的进化和功能多样化
Kouji Uda1, Rie Nishimura2, Yuexuan Li2
1Laboratory of Biochemistry, Faculty of Science and Technology, Kochi University, Kochi, 780-8520, Japan. k-uda@kochi-u.ac.jp.
Journal of molecular evolution
|January 17, 2025
概括
细菌血清酶赛马酶 (SerR) 同类物,与广泛的动物形式不同,表现出多样化的酶活性,包括阿金氨酸赛马酶. 这表明基质特异性的独立进化来自共同的祖先,由关键氨基酸残留驱动.
科学领域:
- 生物化学和分子生物学
- 进化生物学 进化生物学
- 酶学 是一种酶学.
背景情况:
- 氨基酸种族酶相互转换L-和D-氨基酸,对于细胞平衡至关重要.
- 血清赛马酶 (SerR) 主要在动物中发现,最近发现了细菌同类物,但人们对其了解甚少.
- 细菌SerR同类的进化分布和功能作用在很大程度上仍未被探索.
研究的目的:
- 为了研究细菌血清酶种族酶 (SerR) 同类的进化起源和功能多样性.
- 从各种细菌物种中克隆的SerR同类体的酶性活动的特征.
- 阐明SerR同类物中基质特异性和催化活性的分子基础.
主要方法:
- 克隆和表达了来自13种细菌物种的20个SerR同源基因.
- 描述了各种氨基酸的酶性活动,包括血清脱水酶和种族酶活动.
- 进行了遗传学分析,氨基酸序列对齐和局部定向突变发生.
主要成果:
- 六种细菌的SerR同类体表现出氨酸脱水酶活性.
- 其余的SerR同类体显示了对氨酸,酸盐,氨酸或氨酸的种族酶活性.
- 几种细菌的SerR同类体显示出显著的阿尔金因种族酶活性,特定的动力参数 (Km,kcat) 已确定.
- 遗传学分析表明,细菌和真核生物的SerR同类基因具有共同的祖先基因.
- 在基质结合部位附近的残留物 (位置146-148),被确定为基质特异性和/或催化活性至关重要.
结论:
- 细菌和真核生物的SerR同类共享一个共同的进化起源.
- 在SerR同类物中,基质特异性已经多次独立演变.
- 特定的氨基酸残留在确定SerR同类的功能多样化方面发挥着关键作用.
相关概念视频
Bacterial RNA Polymerase
28.5K
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
28.5K
Gene Evolution - Fast or Slow?
7.0K
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
7.0K
Conservative Site-specific Recombination and Phase Variation
5.9K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
5.9K
Bacterial Transcription
27.9K
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
27.9K
tRNA Activation
18.9K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
18.9K
Gene Conversion
9.7K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
9.7K


