Cloning and characterization of a region responsible for the maintenance of megaplasmid pTAV3 of Paracoccus versutus UW1

Department of Bacterial Genetics, Institute of Microbiology, Warsaw University, Miecznikowa 1, 02-096 Warsaw, Poland.
Plasmid (Impact Factor: 1.58). 06/2005; 53(3):239-50. DOI: 10.1016/j.plasmid.2004.11.005
Source: PubMed


Using cointegrate formation, we constructed a basic replicon of the megaplasmid/mini-chromosome pTAV3 of Paracoccus versutus UW1. It is composed of two adjacent modules, responsible for plasmid replication (rep) and partitioning (par). Functional analysis of the par region identified a determinant of incompatibility (inc2), whose presence is crucial for proper partitioning (the partitioning site). Database searches revealed that the only known replicon with significant homology to that of pTAV3 is encoded by the chromosome cII of Rhodobacter sphaeroides 2.4.1. Incompatibility studies showed that closely related basic replicons are also encoded by megaplasmids (above 400 kb) harbored by four strains of P. pantotrophus. Basic replicons of the pTAV3-type are able to maintain large bacterial genomes, therefore they appear to be good candidates for the construction of vectors specific for Alphaproteobacteria.

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Available from: Dariusz Bartosik
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    • "[5]). As a result of this approach we have identified and analyzed (i) four related repABC as well as several pTAV3-type megaplasmids – both groups residing in P. versutus UW1 and four strains of Paracoccus pantotrophus [6,7], (ii) plasmid pALC1 of Paracoccus alcaliphilus JCM 7364, with an iteron-containing replication system [8], (iii) plasmid pMTH1 of Paracoccus methylutens DM12, whose genome is predominantly (80%) composed of transposable modules (TMos) [9], (iv) three plasmids of Paracoccus aminophilus JCM 7686, whose REP modules were used for the construction of versatile DIY cassettes [10,11], as well as (v) plasmid pWKS1 of P. pantotrophus DSM 11072 – the smallest replicon identified so far in Paracoccus spp. [12]. "
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