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User:Dudleydoodog/Trp operon

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Existing Article: Trp Operon

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The bolded sentences are my own.

Genes

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Trp operon contains five structural genes. Their roles are

Regulation of trp operon in Bacillus subtilis

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Trp operon genes are arranged in the same order in E. coli and Bacillus subtilis. [1] The arrangement of the trp operon in E. coli and Bacillus subtilis differs. There are 5 structural genes in E. coli that are found under a single transcriptional unit. In Bacillus subtilis, there are 6 structural genes that are situated within a supraoperon. Three of these genes are found upstream while the other three genes are found downstream of the trp operon. [2] There is a 7th gene in Bacillus subtilis's operon called trpG or pabA which is responsible for protein synthesis of tryptophan and folate. [3] Regulation of trp operons in both organisms depends on the amount of trp present in the cell. However, the primary regulation of tryptophan biosynthesis in B. subtilis is via attenuation, rather than repression, of transcription.[4] In B. subtilis, tryptophan binds to the eleven-subunit tryptophan-activated RNA-binding attenuation protein (TRAP), which activates TRAP's ability to bind to the trp leader RNA.[5][6] Binding of trp-activated TRAP to leader RNA results in the formation of a terminator structure that causes transcription termination.[4] In addition, the activated TRAP inhibits the initiation of translation of trpP, trpE, trpG and ycbK genes. The gene trpP plays a role in trp transportation, while the gene trpG is utilized in the folate operon, and the gene ycbK is involved in synthesis of an efflux protein. The activated TRAP protein is regulated by an anti-TRAP protein and AT synthesis. AT can inactive TRAP to lower the transcription of tryptophan. [7]

  1. ^ Merino E, Jensen RA, Yanofsky C (April 2008). "Evolution of bacterial trp operons and their regulation". Current Opinion in Microbiology. 11 (2): 78–86. doi:10.1016/j.mib.2008.02.005. PMC 2387123. PMID 18374625.
  2. ^ Yanofsky, Charles (2004). The different roles of tryptophan transfer RNA in regulating trp operon expression in E. coli versus B. subtilis (20 ed.). Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA: Oxford: Elsevier Ltd. pp. 367–369. doi:10.1016/j.tig.2004.06.007.{{cite book}}: CS1 maint: location (link)
  3. ^ Yang, Wen-Jen; Yanofsky, Charles (2005-03-15). "Effects of Tryptophan Starvation on Levels of the trp RNA-Binding Attenuation Protein (TRAP) and Anti-TRAP Regulatory Protein and Their Influence on trp Operon Expression in Bacillus subtilis". Journal of Bacteriology. 187 (6): 1884–1891. doi:10.1128/JB.187.6.1884-1891.2005. ISSN 0021-9193. PMC 1064063. PMID 15743934.{{cite journal}}: CS1 maint: PMC format (link)
  4. ^ a b Gollnick P, Babitzke P, Antson A, Yanofsky C (2005-11-14). "Complexity in regulation of tryptophan biosynthesis in Bacillus subtilis". Annual Review of Genetics. 39 (1): 47–68. doi:10.1146/annurev.genet.39.073003.093745. PMID 16285852.
  5. ^ Elliott MB, Gottlieb PA, Gollnick P (January 2001). "The mechanism of RNA binding to TRAP: initiation and cooperative interactions". RNA. 7 (1): 85–93. doi:10.1017/S135583820100173X. PMC 1370072. PMID 11214184.
  6. ^ Antson AA, Otridge J, Brzozowski AM, Dodson EJ, Dodson GG, Wilson KS, et al. (April 1995). "The structure of trp RNA-binding attenuation protein". Nature. 374 (6524): 693–700. Bibcode:1995Natur.374..693A. doi:10.1038/374693a0. PMID 7715723. S2CID 4340136.
  7. ^ Cruz-Vera, Luis R.; Gong, Ming; Yanofsky, Charles (2008-03-15). "Physiological Effects of Anti-TRAP Protein Activity and tRNA Trp Charging on trp Operon Expression in Bacillus subtilis". Journal of Bacteriology. 190 (6): 1937–1945. doi:10.1128/JB.01820-07. ISSN 0021-9193. PMC 2258860. PMID 18178730.{{cite journal}}: CS1 maint: PMC format (link)