根据能力T4P的DNA结合的分子基础在代表性格拉姆阳性和格拉姆阴性物种中是不同的
Nicholas D Christman1, Ankur B Dalia1
1Department of Biology, Indiana University, Bloomington, Indiana, United States of America.
PLoS pathogens
|April 21, 2025
概括
第四类 pili (T4P) 在细菌中调解DNA吸收. 在像Streptococcus pneumoniae这样的格拉姆阳性细菌中,DNA结合的自然转化依赖于ComGF小,而不是ComGD,揭示了格拉姆阳性和格拉姆阴性物种之间不同的DNA结合机制.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 细菌遗传学 细菌遗传学
背景情况:
- 第四类 pili (T4P) 是关键的细菌表面结构,在自然转化过程中参与DNA吸收.
- 能力T4P存在于格拉姆阴性 (双皮体) 和格拉姆阳性 (单皮体) 细菌中,促进横向基因转移.
- 在格兰阴性细菌中,DNA结合能力T4P的机制得到了很好的研究,但在格兰阳性细菌中仍然很大程度上未知.
研究的目的:
- 通过T4P的能力来研究DNA结合的机制,在格兰阳性细菌中Streptococcus pneumoniae.
- 为了比较单体能力T4P中小柱子的DNA结合作用与双体能力T4P中的同类.
主要方法:
- 使用Streptococcus pneumoniae作为一个模型生物来研究单体能力T4P.
- 通过使用遗传方法,研究了小柱子ComGD和ComGF中保存的正电荷残留物的作用.
- 评估了突变在自然转化过程中对DNA吸收的影响.
主要成果:
- 在ComGD (diderm FimT的同类物) 中的带正电荷的残留物在S. pneumoniae.的自然转化过程中在DNA吸收中起到很小的作用.
- 邻近的小皮林ComGF (diderm PilW的同类物) 中的两个带正电荷的残留物是关键的,并在DNA吸收中发挥主导作用.
- 在ComGF中的这些关键残留物在其他单体细菌中保存,但在二体细菌中没有保存.
结论:
- 通过能力T4P的DNA结合的分子基础在格拉姆阳性 (单体) 和格拉姆阴性 (双体) 细菌之间有所不同.
- 而不是ComGD,ComGF是DNA结合的主要决定因素,用于像S. pneumoniae这样的单体细菌的自然转化.
- 这些发现突出了DNA结合机制在不同细菌细胞外类型的T4P能力的独立进化.
相关概念视频
Single-Strand DNA Binding Proteins
13.7K
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
13.7K
Genomic DNA in Prokaryotes
43.0K
The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the nucleoid. The chromosome is tightly wound, or supercoiled, for efficient storage. Prokaryotes also contain other circular pieces of DNA called plasmids. These plasmids are smaller than the chromosome and often carry genes that confer adaptive functions, such as antibiotic resistance.
Genomic Diversity in Bacteria
Although bacterial genomes are much...
Genomic Diversity in Bacteria
Although bacterial genomes are much...
43.0K
Prokaryotic Transcriptional Activators and Repressors
20.2K
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
20.2K
Cytoskeletal Proteins in Bacteria
3.2K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.2K
Cooperative Binding of Transcription Regulators
6.2K
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form...
6.2K
Bacterial RNA Polymerase
28.0K
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...
28.0K


