T4噬菌體

T4噬菌體
病毒分類
（未分級）：	病毒 Virus
域：	雙鏈DNA病毒域 Duplodnaviria
界：	香港病毒界 Heunggongvirae
門：	尾噬菌體門 Uroviricota
綱：	有尾噬菌體綱 Caudoviricetes
目：	有尾噬菌體目 Caudovirales
科：	肌尾噬菌體科 Myoviridae
屬：	T4噬菌體屬 T4virus
種：	T4噬菌體 Enterobacteria phage T4

T4噬菌體是噬菌體的一個品系，屬於T－系噬菌體，為烈性噬菌體。具有典型的蝌蚪狀外形：六角形的頭部和可收縮的長的尾部。頭部的蛋白質外殼內含有摺疊的DNA分子；尾部的蛋白質外殼為一中空的長管，外面包有可收縮的尾鞘。頭部大小為65*95nm，頸部長95nm，尾部120nm。

介紹

侵染寄主時，尾鞘收縮，頭部的DNA即通過中空的尾部注入細胞內。T－系噬菌體是研究最廣泛和深入的細菌噬菌體，侵染大腸桿菌（一種正常棲居在人類腸道中的細菌）B菌株，T為英文Type的字頭，並按其發現的前後順序編號為T1，2，3，4，5，6，7，因其偶數型（2，4，6）結構的化學組成與奇數型（1，3，5，7）不同，故又分為T－偶數系與T－奇數系。例：T4屬偶數系。

結構

其構造屬複合對稱體制。因結構簡單、遺傳背景清楚、增殖容易、對人無害，故是迄今被研究得最透徹、在病毒學和分子遺傳學研究中應用最廣泛的模式生物之一。構造分頭部、頸部和尾部3部分。頭部呈拉長的二十面體結構，長95nm，寬65 nm，衣殼由9～19種蛋白質組成，蛋白質含量占 76%～81%，含有直徑為6nm的衣殼粒212個。核心由線狀dsDNA組成，長約50μm(約為頭長的650倍)，由1.7×10bp構成(包括約2.3%末端冗餘)。 DNA成分特殊，以5-羥甲基胞嘧啶(HMC)取代常見的胞嘧啶。頭、尾部相連處有一頸部，包括頸環和頸鬚，前者為一六角形盤狀結構，直徑37.5nm，每一角上各長一頸鬚，用以裹住吸附前的尾絲。長而可收縮的尾部由尾鞘、尾管、基板、刺突和尾絲5部分組成。尾鞘長95、寬22 nm，是一種由相對分子質量為55 000的衣殼粒共144個纏繞而成的24環螺旋組成。尾管長95 nm，直徑8nm，中央孔道的直徑為2.5～3.5 nm，它是頭部核酸即基因組注入寄主細胞時的必經之路。尾管亦由24環螺旋組成，與尾鞘相對應。基板與頸環相似，為一有中央尾孔的六角形盤狀物，直徑為30.5 nm，上長6個刺突和6根尾絲。刺突長20nm，有吸附功能。尾絲可折成2段，長140nm，直徑3～ 4nm，由2種相對分子質量較大的蛋白質和4種相對分子質量較小的蛋白質組成，能專一地吸附在敏感寄主細胞表面的相應受體上。T4的尾孔至少含溶菌酶等8種蛋白質。3種T偶數噬菌體在寄主細胞表面有不同的吸附位點：T4在大腸埃希氏菌(Escherichia coli)B菌株上的吸附位點是LPS核心多糖中的α-葡糖基-(1→3)葡萄糖末端，在K菌株上則為LPS或外膜蛋白 OmpC。科學家們在T4噬菌體中發現了一種酶，稱為T4-DNA連接酶，在轉基因技術中用作黏性末端和平末端的連接酶。對平末端連接效率低下。

參考

^ Padilla-Sanchez, Victor. Structural Model of Bacteriophage T4. WikiJournal of Science. 2021, 4 (1): 5 [2021-08-06]. doi:10.15347/WJS/2021.005. （原始內容存檔於2022-04-28）.

延伸閱讀

Padilla-Sanchez, Victor. Structural Model of Bacteriophage T4. WikiJournal of Science. 2021, 4 (1): 5 [2021-08-06]. doi:10.15347/WJS/2021.005. （原始內容存檔於2022-04-28）.
Leiman P.G.; Kanamaru S; Mesyanzhinov V.V.; Arisaka F.; Rossmann M.G. Structure and morphogenesis of bacteriophage T4.. Cellulal and Molecular Life Sciences CMLS. 2003, 60 (11): 2356–2370. doi:10.1007/s00018-003-3072-1.
Karam, J., Petrov, V., Nolan, J., Chin, D., Shatley, C., Krisch, H., and Letarov, A. The T4-like phages genome project. https://web.archive.org/web/20070523215704/http://phage.bioc.tulane.edu/. (The T4-like phage full genomic sequence depository)
Mosig, G., and F. Eiserling. 2006. T4 and related phages: structure and development, R. Calendar and S. T. Abedon (eds.), The Bacteriophages. Oxford University Press, Oxford. (Review of phage T4 biology) ISBN 0-19-514850-9
Filee J. Tetart F.; Suttle C.A.; Krisch H.M. Marine T4-type bacteriophages, a ubiquitous component of the dark matter of the biosphere. Proc. Natl. Acad. Sci. USA. 2005, 102 (35): 12471–6 [2018-04-08]. PMC 1194919 . PMID 16116082. doi:10.1073/pnas.0503404102. （原始內容存檔於2008-06-20）. (Indication of prevalence and T4-like phages in the wild)
Chibani-Chennoufi S.; Canchaya C.; Bruttin A.; Brussow H. Comparative genomics of the T4-Like Escherichia coli phage JS98: implications for the evolution of T4 phages. J. Bacteriol. 2004, 186 (24): 8276–86 [2018-04-08]. PMC 532421 . PMID 15576776. doi:10.1128/JB.186.24.8276-8286.2004. （原始內容存檔於2011-05-11）. (Characterization of a T4-like phage)
Desplats C, Krisch HM. The diversity and evolution of the T4-type bacteriophages. Res. Microbiol. May 2003, 154 (4): 259–67 [2018-04-08]. PMID 12798230. doi:10.1016/S0923-2508(03)00069-X. （原始內容存檔於2019-02-18）.
Miller, E.S.; Kutter E.; Mosig G.; Arisaka F.; Kunisawa T.; Ruger W. Bacteriophage T4 genome. Microbiol. Mol. Biol. Rev. 2003, 67 (1): 86–156 [2018-04-08]. PMC 150520 . PMID 12626685. doi:10.1128/MMBR.67.1.86-156.2003. （原始內容存檔於2011-05-11）. (Review of phage T4, from the perspective of its genome)
Desplats C.; Dez C.; Tetart F.; Eleaume H.; Krisch H.M. Snapshot of the genome of the pseudo-T-even bacteriophage RB49. J. Bacteriol. 2002, 184 (10): 2789–2804 [2018-04-08]. PMC 135041 . PMID 11976309. doi:10.1128/JB.184.10.2789-2804.2002. （原始內容存檔於2011-05-11）. (Overview of the RB49 genome, a T4-like phage)
Malys N, Chang DY, Baumann RG, Xie D, Black LW. A bipartite bacteriophage T4 SOC and HOC randomized peptide display library: detection and analysis of phage T4 terminase (gp17) and late sigma factor (gp55) interaction. J Mol Biol. 2002, 319 (2): 289–304. PMID 12051907. doi:10.1016/S0022-2836(02)00298-X. (T4 phage application in biotechnology for studying protein interaction)
Tétart F.; Desplats C.; Kutateladze M.; Monod C.; Ackermann H.-W.; Krisch H.M. Phylogeny of the major head and tail genes of the wide-ranging T4-type bacteriophages. J. Bacteriol. 2001, 183 (1): 358–366 [2018-04-08]. PMC 94885 . PMID 11114936. doi:10.1128/JB.183.1.358-366.2001. （原始內容存檔於2011-05-11）. (Indication of the prevalence of T4-type sequences in the wild)
Abedon S.T. The murky origin of Snow White and her T-even dwarfs. Genetics. 2000, 155 (2): 481–6 [2018-04-08]. PMC 1461100 . PMID 10835374. （原始內容存檔於2011-01-28）. (Historical description of the isolation of the T4-like phages T2, T4, and T6)
Ackermann HW, Krisch HM. A catalogue of T4-type bacteriophages. Arch. Virol. 1997, 142 (12): 2329–45 [2018-04-08]. PMID 9672598. doi:10.1007/s007050050246. （原始內容存檔於2001-11-01）. (Nearly complete list of then-known T4-like phages)
Monod C, Repoila F, Kutateladze M, Tétart F, Krisch HM. The genome of the pseudo T-even bacteriophages, a diverse group that resembles T4. J. Mol. Biol. March 1997, 267 (2): 237–49 [2018-04-08]. PMID 9096222. doi:10.1006/jmbi.1996.0867. （原始內容存檔於2019-02-18）. (Overview of various T4-like phages from the perspective of their genomes)
Kutter E.; Gachechiladze K.; Poglazov A.; Marusich E.; Shneider M.; Aronsson P.; Napuli A.; Porter D.; Mesyanzhinov V. Evolution of T4-related phages. Virus Genes. 1995, 11 (2–3): 285–297. PMID 8828153. doi:10.1007/BF01728666. ^{[永久失效連結]} (Comparison of the genomes of various T4-like phages)
Karam, J. D. et al. 1994. Molecular Biology of Bacteriophage T4. ASM Press, Washington, DC. (The second T4 bible, go here, as well as Mosig and Eiserling, 2006, to begin to learn about the biology T4 phage) ISBN 1-55581-064-0
Eddy, S. R. 1992. Introns in the T-Even Bacteriophages. Ph.D. thesis. University of Colorado at Boulder. (Chapter 3 provides overview of various T4-like phages as well as the isolation of then-new T4-like phages)
Surdis, T.J "et al" Bacteriophage attachment methods specific to T4, analysis, Overview.
Mathews, C. K., E. M. Kutter, G. Mosig, and P. B. Berget. 1983. Bacteriophage T4. American Society for Microbiology, Washington, DC. (The first T4 bible; not all information here is duplicated in Karam et al., 1994; see especially the introductory chapter by Doermann for a historical overview of the T4-like phages) ISBN 0-914826-56-5
Russell, R. L. 1967. Speciation Among the T-Even Bacteriophages. Ph.D. thesis. California Institute of Technology. (Isolation of the RB series of T4-like phages)
Malys N, Nivinskas R. Non-canonical RNA arrangement in T4-even phages: accommodated ribosome binding site at the gene 26-25 intercistronic junction. Mol Microbiol. 2009, 73 (6): 1115–1127. PMID 19708923. doi:10.1111/j.1365-2958.2009.06840.x. (rare type of translational regulation characterized in T4)
Kay D.; Fildes P. Hydroxymethylcytosine-containing and tryptophan-dependent bacteriophages isolated from city effluents. J. Gen. Microbiol. 1962, 27: 143–6. PMID 14454648. doi:10.1099/00221287-27-1-143. (T4-like phage isolation, including that of phage Ox2)