原核和真核核糖核酸的区别Polymerase

关键的区别——原核和真核RNA聚合酶ymerase

RNA聚合酶是负责在所有生物体中发生的转录过程的酶。RNA聚合酶是一种高分子量酶。RNA聚合酶的官方名称是DNA-directed RNA polymerase. During thetranscription，RNA聚合酶打开双链DNA，这样一个DNAstrand can be used as a template for the process of synthesizing amRNA分子。生成RNA（mRNA，rRNA， 和tRNA) molecules is an extremely important step in theprotein synthesis(translation). Transcription factors and transcription mediated complexes are guiding the RNA polymerase enzyme to initiate the transcription in a living cell. RNA polymerase attaches to the promoter region of the gene (DNA) and starts the RNA polymerase-catalyzed transcription.原核和真核转录主要是由于RNA聚合酶酶的差异而不同。这关键区别在原核和真核RNA聚合酶之间是the prokaryotic transcription is performed by a single multi subunit type of RNA polymerase. On the contrary, the eukaryotic transcription is catalyzed by three different types of RNA polymerases named as RNA polymerase I（转录RRNA），RNA聚合酶II（转录mRNA）和RNA聚合酶III（转录tRNA）。

CONTENTS

1.概述和关键差异
2.What is Prokaryotic RNA Polymerase
3.什么是真核RNA聚合酶
4。Similarities Between Prokaryotic and Eukaryotic RNA Polymerase
5。并排比较 - 核核酸与真核RNA聚合酶以表格形式
6。Summary

What is Prokaryotic RNA Polymerase?

这prokaryotic RNA polymerase is a multisubunit heavy enzyme. The RNA polymerase ofE coli经过广泛的研究。这是一种复杂的酶，其分子量为450 kDa。这全酶consists of two main components. They are core enzyme and transcription factors. The core enzyme component is having five subunits such as β’, β, αI, αII and ω. The transcription factors are sigma factor (initiation), nusA (elongation).

在这些因素中，β´具有DNA结合的功能。β因子具有进行RNA聚合的催化位点。尚未发现因子α和ω的功能。有人说，α因子（α）负责链启动和与调节蛋白的相互作用。Sigma因子的主要功能是启动子识别。一旦DNA中的启动子被Sigma因子识别coenzymecomponent of the RNA polymerase binds with promoter region and initiates the RNA polymerization. Once transcription begins the sigma factor releases from the DNA. The elongation of RNA molecule is done by β subunit. In the chain termination, the “rho factor” releases the already-transcribed RNA molecule.

转录终止于DNA模板指定的位点。NUSA因子参与伸长和链终止的功能。抗生素利福平可以与细菌RNA聚合酶的β亚基结合。因此，它可以防止酶引发细菌RNA聚合。另一种称为链氨二基蛋白的抗生素抑制细菌RNA聚合的伸长过程。原核生物mRNA是多物质的，这意味着它包含密码子of a more than one cistron (more than one gene).

什么是真核RNA聚合酶？

这eukaryotic RNA polymerases are three different types. They transcribe different classes of genes. And also function under different conditions. The initiating and terminating factors (sigma and rho factors) are completely different from prokaryotic RNA polymerase counterparts. The three different RNA polymerases are named as, RNA polymerase I (transcribes rRNA), RNA polymerase II (transcribes mRNA) and RNA polymerase III (transcribes tRNA). RNA polymerase I is located in thenucleolusand the enzyme is requiring Mg²⁺为了它的活动。RNA聚合酶II在核质中，需要ATP才能进行活性。RNA聚合酶III也位于核质中。

这些RNA聚合酶的启动子不同。RNA聚合酶I识别在DNA中-45至+25个区域之间上游的启动子。RNA聚合酶II识别上游-25至-100区域中DNA中的启动子，例如（TATA盒，CAAT盒和GC盒）。RNA聚合酶III识别下游的内部​​启动子。

这eukaryotic RNA polymerases are large complex that made up of multi subunits proteins of 500 kDa or more. They have different transcription factors for initiation process and elongation process like, TFIIA, TFIIB, TFIID, TFIIE, TFIIF, TFIIH, TFIIJ. RNA polymerization terminates by RNA polymerase I after recognizing Sal box. RNA polymerization termination by RNA polymerase II happens after recognizing downstream signals known as polyA tail. And RNA polymerase III recognizes deoxyadenylate residues on the template and terminate the transcription. Eukaryotic mRNA is always monocistronic.

What are the Similarities Between Prokaryotic and Eukaryotic RNA Polymerase?

• 两者都参与RNA合成。
• Both are using DNA as the template.
• Both are large proteins.
• 两者都有启动转录的Sigma因子。
• 两者都有调节RNA聚合的步骤（启动和伸长）的转录因子。

原核和真核RNA聚合酶有什么区别？

原核生物与真核RNA聚合酶
原核RNA聚合酶是一种单个多亚基类型酶，负责原核转录。	这Eukaryotic RNA polymerases are different types of enzymes which carry out the eukaryotic transcription.
Molecular Weight
原核RNA聚合酶分子量约为400 kDa。	真核RNA聚合酶分子量超过500kd。
Transcription Factors
这prokaryotic RNA polymerase has transcription factors such as sigma factor and nusA.	真核RNA聚合酶具有不同的转录因子来引发和伸长，例如；tfiia，tfiib，tfiid，tfiie，tfiif，tfiih，tfiij
Termination Factor
这prokaryotic RNA polymerase has “rho factor” for termination.	真核RNA聚合酶具有不同的终止序列，例如SAL盒，Poly A尾巴，脱氧二腺苷酸残基。
Promoters
这prokaryotic RNA polymerase recognizes promoter in -10 to -35 region in DNA known as TATA box.	这Eukaryotic RNA polymerases recognize different promoters1.
mRNA的性质
原核RNA聚合酶会产生多用电话mRNA。	这Eukaryotic RNA polymerase II produces monocistronic mRNA.

¹RNA聚合酶I。识别在DNA中-45至+25区域之间上游的启动子。RNA聚合酶I。I在-25至-100区域的DNA（例如（Tata Box，Caat Box和GC盒）中的-25至-100区域之间的启动子中识别启动子。RNA聚合酶I。II认识下游的内部​​启动子。

Summary –原核生物与真核RNA聚合酶

RNA聚合酶is the enzyme responsible for RNA polymerization known as transcription in the living cell. The RNA polymerase is also named as DNA-directed RNA polymerase as it uses DNA as the template. In transcription RNA polymerase normally opens the double-stranded DNA so that one DNA strand can be used as a template for the process of synthesizing RNA molecule. RNA polymerase can give rise to mRNA, rRNA, and tRNA. Transcription factors and transcription mediated complex are guiding the RNA polymerase in the transcription process. The transcription has three steps; initiation, elongation, and termination. This can be highlighted as the difference between Prokaryotic and Eukaryotic RNA Polymerase.

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Reference:

1.Nature News, Nature Publishing Group.Available here
2.“RNA polymerase.” Wikipedia, Wikimedia Foundation, 11 Dec. 2017.Available here

Image Courtesy:

1.’RNAP TEC small’By Abbondanzieri, ( Public Domain) via下议院维基梅迪亚
2.’Label RNA pol II’ By JWSchmidt, (Public Domain) via下议院维基梅迪亚