DNA聚合酶

人类DNA聚合酶β中螺旋-转角-螺旋基序的三维模型

DNA聚合酶（DNA Polymerase，EC編號2.7.7.7）是一種參與DNA複製的酶。它主要是以模板的形式，催化去氧核糖核苷酸的聚合。聚合後的分子將會組成模板鏈並再進一步參與配對。


DNA replication

DNA聚合酶以去氧核苷酸三磷酸（dATP、dCTP、dGTP、或dTTP，四者統稱dNTPs）為底物，沿模板的3'→5'方向，將對應的去氧核苷酸連接到原有DNA鏈的3'端，使新生鏈沿5'→3'方向延長。新鏈與原有的模板鏈序列互補，亦與模板鏈的原配對鏈序列一致。

已知的所有DNA聚合酶均以5'→3'方向合成DNA，且均不能「重新」（de novo）合成DNA，而只能將去氧核苷酸加到已有的RNA或DNA的3'端羥基上。因此，DNA聚合酶除了需要模板做為序列指導，也必需引物來起始合成。合成引物的酶叫做引發酶。

反應式：

歷史

1957年，美國科學家阿瑟·科恩伯格（Arthur Kornberg）首次在大腸桿菌中發現DNA聚合酶，這種酶被稱為DNA聚合酶I（DNA polymerase I，簡稱：Pol I）。1970年，德國科學家羅爾夫·克尼佩爾斯（Rolf Knippers）發現DNA聚合酶II（Pol II）。隨後，DNA聚合酶III（Pol III）被發現。原核生物中主要的DNA聚合酶及負責染色體複製的是Pol III。

種類

原核生物

細菌中，已有數種DNA聚合酶被發現。

  • DNA聚合酶I（Pol I）：大腸桿菌K-12株的DNA聚合酶I由基因polA編碼，由928個氨基酸組成，分子量103.1kDa，結構類似球狀，直徑約6.5nm，每個細胞約有400個分子。
  • DNA聚合酶II（Pol II）：作用於DNA稳定期的损伤修复
  • DNA聚合酶III（Pol III）：作用於大肠杆菌DNA复制过程中
  • DNA聚合酶IV（Pol IV）：与DNA聚合酶II一起负责稳定期的损伤修复。
  • DNA聚合酶V（Pol V）：参与SOS修复。
  • D族DNA聚合酶（family D）

真核生物

  • Pol α：與引发酶(DNA Primase)形成複合體(Pol α-primase complex)，合成約10nt RNA引子，然後做為DNA合成酶延伸此段RNA引子；合成約20個鹼基(iDNA)後，將後續的延伸過程交給Pol δ與ε。
  • Pol β：在DNA修復中起作用，低保真度的复制
  • Pol γ：複製線粒體DNA。
  • Pol δ：Pol δ與Pol ε是真核細胞的主要DNA聚合酶。用於延遲股(lagging strand)合成
  • Pol ε：填补引物空隙，切除修复，重组，用於領導股(Leading strand)合成
  • Pol ζ：

DNA聚合酶介导的DNA合成

DNA链延伸的亲核取代机理

DNA聚合酶介导的DNA合成起始于引物（primer）和DNA配对，配对的引物3'端带有一个自由的羟基，随后是在DNA聚合酶的催化下由这个自由羟基氧上的配对电子攻击三磷酸碱基上的磷原子的亲核取代，继而在戊糖和磷酸之间形成脂键从而完成一个碱基的延伸。

在整个过程中，能量是由三磷酸碱基所携带的高能磷酸键提供的，磷酸酯形成以后，一个焦磷酸分子脱落，焦磷酸分子再次分裂提供足够的能量给DNA聚合过程。

不同的DNA聚合酶廣泛應用於分子生物學實驗[1]。

內部連結

參考資料

  1. ^ DNA聚合酶. 来邦网. [2010-01-25]. （原始内容存档于2019-09-24）. 

Read other articles:

Глубокое обучение

У этого термина существуют и другие значения, см. Глубокое обучение (значения). Глубокое обучение (глубинное обучение; англ. Deep learning) — совокупность методов машинного обучения (с учителем, с частичным привлечением учителя, без учителя, с подкреплением), основанных на ...

 

 

Microtus ilaeus

Tien Shan vole Microtus ilaeus Status konservasiRisiko rendahIUCN13438 TaksonomiKerajaanAnimaliaFilumChordataKelasMammaliaOrdoRodentiaFamiliCricetidaeGenusMicrotusSpesiesMicrotus ilaeus Tata namaSinonim taksonMicrotus kirgisorum (Ognev, 1950)lbs Microtus ilaeus adalah sebuah spesies hewan pengerat dalam keluarga Cricetidae. Spesies tersebut ditemukan di Afganistan, Kazakhstan, Kirgizstan, Tajikistan, dan Turkmenistan. Referensi Baillie, J. 1996. Microtus kirgisorum. 2006 IUCN Red List of Thre...

 

 

Honey badger

Species of mammal Ratel redirects here. For other uses, see Honey Badger (disambiguation) and Ratel (disambiguation). Honey badgerTemporal range: middle Pliocene – Recent In Kruger National Park, South Africa Conservation status Least Concern  (IUCN 3.1)[1] Scientific classification Domain: Eukaryota Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Mustelidae Subfamily: Mellivorinae Genus: Mellivora Species: M. capensis Binomial name Mellivora ca...

Åke Andersson (footballer, born 1917)

Swedish footballer (1917–1983) Åke Andersson Personal informationDate of birth (1917-04-22)22 April 1917Place of birth Gothenburg, SwedenDate of death 20 July 1983(1983-07-20) (aged 66)Position(s) ForwardSenior career*Years Team Apps (Gls)1935–1939 GAIS 1939–1946 AIK International career1937–1941 Sweden 12 (2) *Club domestic league appearances and goals Åke Andersson (22 April 1917 – 20 July 1983) was a Swedish football forward who played for Sweden in the 1938 FIFA World Cup...

 

 

Человек прямоходящий

† Человек прямоходящий Научная классификация Домен:ЭукариотыЦарство:ЖивотныеПодцарство:ЭуметазоиБез ранга:Двусторонне-симметричныеБез ранга:ВторичноротыеТип:ХордовыеПодтип:ПозвоночныеИнфратип:ЧелюстноротыеНадкласс:ЧетвероногиеКлада:АмниотыКлада:Синапсиды�...

 

 

Citilink

Low-cost airline of Indonesia For other uses, see Citylink (disambiguation). Citilink IATA ICAO Callsign QG CTV SUPERGREEN Commenced operations16 July 2001; 22 years ago (2001-07-16)HubsJakarta–Halim PerdanakusumaJakarta–Soekarno-HattaSurabayaSecondary hubsBatamDenpasarMakassarMedanFrequent-flyer programSupergreen GarudaMilesFleet size59Destinations51[1]Parent companyGaruda IndonesiaHeadquartersJakarta, IndonesiaKey peopleDewa Kadek Rai (CEO)[2]Operating ...

1908 in India

India-related events during the year of 1908 ← 1907 1906 1905 1908 in India → 1909 1910 1911 Centuries: 18th 19th 20th 21st Decades: 1880s 1890s 1900s 1910s 1920s See also:List of years in IndiaTimeline of Indian history Events in the year 1908 in India. Incumbents Emperor of India – Edward VII Viceroy of India – Gilbert Elliot-Murray-Kynynmound, 4th Earl of Minto Events National income - ₹10,373 million March 17 – the Tinnevely riot breaks out in Tirunelveli May – the t...

 

 

Hamilton, Montana

City in Montana, United States City in Montana, United StatesHamiltonCityDowntown HamiltonLocation of Hamilton, MontanaCoordinates: 46°14′54″N 114°9′35″W / 46.24833°N 114.15972°W / 46.24833; -114.15972CountryUnited StatesStateMontanaCountyRavalliGovernment • MayorDominic A Farrenkopf [1]Area[2] • Total2.60 sq mi (6.73 km2) • Land2.54 sq mi (6.58 km2) • Water0.06...

 

 

Oceanus (Titan orbiter)

This article is about the Titan orbiter. For the Uranus orbiter, see Oceanus (Uranus orbiter). OceanusOverviewMission typeTitan orbiterOperatorNASASpacecraft propertiesManufacturerLockheed MartinSolar array manufacturerOrbital ATKMission managementNASA / JPLStart of missionExpected flight time10 yearsScience operations4 yearsInstrumentsMass SpectrometerInfrared CameraRadar AltimeterRadio ScienceNew Frontiers Program Oceanus is a NASA/JPL orbiter mission concept proposed in 2017 for the New Fr...

William H. Harries

19th century American politicians For other people named William Harries, see William Harries (disambiguation). William HarriesHarries circa 1911. Houston County Historical Society (Caledonia, MN)Member of the U.S. House of Representativesfrom Minnesota's 1st districtIn officeMarch 4, 1891 – March 3, 1893Preceded byMark H. DunnellSucceeded byJames Albertus Tawney Personal detailsBorn(1843-01-15)January 15, 1843Dayton, Ohio, U.S.DiedJuly 23, 1921(1921-07-23) (aged 7...

 

 

Sepanjang, Glenmore, Banyuwangi

SepanjangDesaPeta lokasi Desa SepanjangNegara IndonesiaProvinsiJawa TimurKabupatenBanyuwangiKecamatanGlenmoreKode pos68466Kode Kemendagri35.10.10.2002 Luas5,74 km²Jumlah penduduk... jiwaKepadatan1.556 jiwa/km² Untuk pengertian lain, lihat Sepanjang. Sepanjang adalah sebuah nama desa di wilayah Glenmore, Kabupaten Banyuwangi, Provinsi Jawa Timur, Indonesia. Pembagian wilayah Desa ini terdiri dari 4 dusun, yaitu: Dusun Sepanjang Kulon Dusun Sepanjang Wetan Dusun Sidoluhur Dusun Sidomulyo...

 

 

UBS

Multinational investment bank headquartered in Switzerland This article is about the investment bank and financial services company. For other uses, see UBS (disambiguation). Not to be confused with the courier company UPS, or United Parcel Service. UBS Group AGHeadquarters in Zürich, SwitzerlandFormerlyUnion Bank of Switzerland (1862–1998)Company typePublic (Aktiengesellschaft)Traded asSIX: UBSGNYSE: UBSSMI componentISINCH0244767585IndustryBankingFinancial servicesPredecessorUni...

Frontex

Frontex Штаб-квартира Frontex в Варшаве Членство Европейское сообщество Расположение Варшава, Польша Тип организации агентство ЕС Основание Ратификация 26 октября 2004 Начало работы 1 мая 2005 Число сотрудников около 700 чел. (2007) более 10 000 чел. (2017) Девиз: лат. «Libertas Securitas Justitia» «Сво�...

 

 

Sam Adekugbe

Canadian soccer player (born 1995) Sam Adekugbe Adekugbe playing for Canada at the 2022 FIFA World CupPersonal informationFull name Samuel Ayomide Adekugbe[1]Date of birth (1995-01-16) January 16, 1995 (age 29)Place of birth London, EnglandHeight 1.78 m (5 ft 10 in)[2][3]Position(s) Left-backTeam informationCurrent team Vancouver Whitecaps FCNumber 3Youth career1998–2000 Manchester United Grassroots Program2000–2004 AFC Clayton2004–2011 Calgar...

 

 

باومهولدر

باومهولدر    شعار   الإحداثيات 49°36′50″N 7°20′00″E / 49.613888888889°N 7.3333333333333°E / 49.613888888889; 7.3333333333333   [1] تقسيم إداري  البلد ألمانيا[2]  التقسيم الأعلى منطقة بيركنفلد  خصائص جغرافية  المساحة 69.19 كيلومتر مربع (31 ديسمبر 2017)[3]  ارتفاع 488 متر ...

Basilika Santo Bonaventura, Lyon

Basilika Santo BonaventuraBasilika Minor Santo Bonaventurabahasa Prancis: Basilique Saint-BonaventureBasilika Santo BonaventuraWikipedia | Kode sumber | Tata penggunaan Koordinat: 45°45′47.32″N 4°50′12.86″E / 45.7631444°N 4.8369056°E / 45.7631444; 4.836905645°45′47″N 4°50′13″E / 45.763144°N 4.836905°E / 45.763144; 4.836905LokasiLyonNegaraPrancisDenominasiGereja Katolik RomaArsitekturStatusBasilika minorStatus fungsion...

 

 

ريس سيتي

ريس سيتي     الإحداثيات 34°04′28″N 86°01′50″W / 34.074446°N 86.03063°W / 34.074446; -86.03063   [1] تقسيم إداري  البلد الولايات المتحدة[2]  التقسيم الأعلى مقاطعة إيتوا  خصائص جغرافية  المساحة 9.207429 كيلومتر مربع9.207425 كيلومتر مربع (1 أبريل 2010)[3]  ارتفاع 173 متر،...

 

 

NGC 2907

NGC 2907   الكوكبة الشجاع[1]  رمز الفهرس NGC 2907 (الفهرس العام الجديد)IRAS F09292-1630 (IRAS)2MASX J09313661-1644051 (Two Micron All-Sky Survey, Extended source catalogue)IRAS 09292-1630 (IRAS)MCG-03-25-002 (فهرس المجرات الموروفولوجي)PGC 27048 (فهرس المجرات الرئيسية)AGC 490091 (Arecibo General Catalog)NVSS J093136-164406 (NRAO VLA Sky Survey)6dFGS gJ093136.6-164405 (6dF Galaxy Survey)LEDA 2704...

Korean Confucianism

Chugyedaeje, a Confucian ritual ceremony in autumn in Jeju, South Korea Part of a series onConfucianism Early history Spring and Autumn period Confucius Warring States period Mencius Xunzi Western Han Dong Zhongshu Gongsun Hong Fundamental concepts Tian Ganying Zhengming Xiao Sangang Wuchang Li Ren Xin Yi Schools Neo-Confucianism Han Learning Taigu school Lingnan Confucianism New Confucianism Progressive Confucianism Hermeneutic schools Old Text New Text Confucianism by country Korea Japan I...

 

 

Live on Blueberry Hill

Live album by Led ZeppelinLive on Blueberry HillLive album by Led ZeppelinRecordedSeptember 4, 1970VenueLos Angeles Forum, Inglewood, CaliforniaLength106:53LabelTrademark of Quality Professional ratingsReview scoresSourceRatingAllMusic[1] Live on Blueberry Hill (also known as Blueberry Hill) is a bootleg recording of English rock group Led Zeppelin's performance at the Los Angeles Forum on September 4, 1970, which took place during their summer 1970 North American Tour.[2...