rna的合成ppt課件-展示頁
2025-05-12 01:53本頁面
【正文】 e (~400 kd) and plex enzyme consisting of four kinds of subunits .The subunit position of the entire enzyme, called the holoenzyme, is a 2 b b s. The s subunit helps find a promoter site where transcription begins, participates in the initiation of RNA synthesis, and then dissociates from the rest of the enzyme. RNA polymerase without this subunit (a 2 b b ) is called the core enzyme. The core enzyme contains the catalytic site. This catalytic site resembles that of DNA polymerase in that it includes two metal ions in its active form. One metal ion remains bound to the enzyme, whereas the other appears to e in with the nucleoside triphosphate and leave with the pyrophosphate. Three conserved aspartate residues of the enzyme participate in binding these metal ions. Note that the overall structures of DNA polymerase and RNA polymerase are quite different。 這段丹霞地貌過去曾長期不被外界了解， 2022年經(jīng)有關(guān)丹霞地貌專家考察，確定其為柱廊狀宮殿式丹霞地貌。這是位于甘肅省酒泉市阿克塞哈薩克族自治縣縣城西約 50公里紅柳溝的柱廊狀宮殿式丹霞地貌局部（ 4月 20日攝）。 甘肅省酒泉市阿克塞哈薩克族自治縣紅柳溝的丹霞地貌呈南北走向、全長約 6公里，處在阿爾金山主峰腳下，以柱廊、宮殿等形狀為主，壯觀美麗，堪稱鬼斧神工。 壯美的南極 第十七章 RNA的生物合成 Key Terms ? transcription ? RNA polymerase ? promoter sites ? transcription factor ? footprinting ? consensus sequence ? sigma subunit ? transcription bubble ? rho (r) protein ? TATA box ? enhancer premRNA 5 cap poly(A) tail RNA editing RNA splicing spliceosome small nuclear RNA (snRNA) alternative splicing catalytic RNA selfsplicing III. Synthesizing RNA的合成過程 包括起始，延伸和終止三個(gè)部分 （ RNA） n +NTP → （ RNA） n +1 + PPi RNA合成需要 。 their similar active sites are the products of convergent evolution. 一 RNA聚合酶 ☆ 19601961年發(fā)現(xiàn)，全酶分子量465000，有五種亞基 組成，含有兩個(gè)鋅原子 ☆ 全酶中無希格碼亞基的酶稱為核心酶，核心酶只能使已開始的 RNA鏈延長，不具有起始合成 RNA的能力 ☆ 希格碼亞基稱為起始亞基 ☆ RNA聚合酶的作用是合成一條與被轉(zhuǎn)錄的DNA互補(bǔ)的反平行的 RNA鏈。 RNA Polymerase Structures. The threedimensional structures of RNA polymerases from a prokaryote (Thermus aquaticus) and a eukaryote (Saccharoromyces cerevisiae). The two largest subunits for each structure are shown in dark red and dark blue. The similarity of these struct
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1