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- Gene expression in Chromobacterium violaceum
- Rosane Silva1, Júlia R. Araripe1, Edson Rondinelli1,2 and Turán P. Ürményi1
- 1Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro,
- Rio de Janeiro, RJ, Brasil
- 2Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil
- Corresponding author: T.P. Ürményi
- E-mail: turmenyi@biof.ufrj.br
- Genet. Mol. Res. 3 (1): 64-75 (2004)
- Received October 13, 2003
- Accepted January 12, 2004
- Published March 31, 2004
ABSTRACT. The repertoire of 4,431 open reading frames (ORFs), eight rRNA operons and 98 tRNA genes of Chromobacterium violaceum must be expressed in a regulated manner for successful adaptation to a wide variety of environmental conditions. To accomplish this feat, the organism relies on protein machineries involved in transcription, RNA processing and translation. Analysis of the C. violaceum genome showed that transcription initiation, elongation and termination are performed by the five well-known RNA polymerase subunits, five categories of sigma 70 factors, one sigma 54 factor, as well as six auxiliary elongation and termination factors. RNA processing is performed by a variety of endonucleases and exonucleases, such as ribonuclease H, ribonuclease E, ribonuclease P, and ribonuclease III, in addition to poly(A) polymerase and specific methyltransferases and pseudouridine synthases. ORFs for all ribosomal proteins, except S22, were found. Only 19 aminoacyl-tRNA synthetases were found, in addition to three aminoacyl-tRNA synthetase-related proteins. Asparaginyl-tRNAAsn is probably obtained by enzymatic modification of a mischarged aminoacyl-tRNA. The translation factors IF-1, IF-2, IF-3, EF-Ts, EF-Tu, EF-G, RF-1, RF-2 and RF-3 are all present in the C. violaceum genome, although the absence of selB suggests that C. violaceum does not synthesize selenoproteins. The components of trans-translation, tmRNA and associated proteins, are present in the C. violaceum genome. Finally, a large number of ORFs related to regulation of gene expression were also found, which was expected, considering the apparent adaptability of this bacterium.
Key words: Chromobacterium violaceum, Gene expression, Gene regulation, Transcription, RNA processing, Translation
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