Plasmídeos naturais de Chromobacterium violaceum: análise de sequências e construção de um vetor para transformação genética

Abstract

Chromobacterium violaceum is a Gram-negative bacteria belonging to the Neisseriaceae family often found in soil and water in tropical and subtropical regions. The biotechnological potential of C. violaceum, due to its peculiar characteristics, led to his choice to be the first bacteria to have its genome sequenced by Brazilian Genome Consortium (MCT / CNPq). A previous study (Vale, R., 2005) identified extra chromosomal DNA molecules in C. violaceum CVT2 samples isolated in fresh waters from Negro in which so far had not been identified C. violaceum bacterial species in this region. Plasmids from C. violaceum CVT2 sample was sequenced by pyrosequencing and analysis " in silico " revealed sequences (contig) that could correspond to three natural plasmids pCVT2.1 , pCVT2.2 and pCVT2.3 so called . The contig 1 (pCVT2.1) with the size of 26.206pb and 84% similarity to plasmid pIJB1 the contig 2 (pCVT2.2) with the size of 7.440pb and 92% similarity to plasmid pRSB105 and contig 4 (pCVT2.3) size of 3062pb and 82% similarity to plasmid pHLHK19. The result of the sequences annotation of these three contigs showed a total of 23 ORFs, being distributed as follows: 18 ORFs located in the plasmid pCVT2.1 7 pCVT2.2 the ORFs, and ORF in plasmid pCVT2.3 1. Research suggests that replication of plasmids and pCVT2.2 pCVT2.3 require a Rep protein and its possible origins of replication with sequences 511and 383pb, respectively, located upstream from the gene Rep.