Complete Nucleotide Sequence of a Novel Plasmid pAT23 from Halopiger sp. AT23 Isolated from Living Stromatolites in the Argentinean Puna

DIB JR, MALDONADO MJ, THÜRMER A, SCHULDES J, DANIEL R, FARÍAS ME

San Miguel de Tucumán

Congreso; VII CONGRESO ARGENTINO DE MICROBIOLOGÍA GENERAL. SAMIGE DEL BICENTENARIO; 2011

Sociedad Argentina de Microbiología General (SAMIGE)

Living or ‘modern’ stromatolites are mostly found in hypersaline lakes and marine lagoons with extreme conditions: high UV incidence, arsenic concentrations, salinity, and oligotrophy [3, 5]. Recently living stromatolites were discovered in Laguna Socompa and Tolar Grande (Fig. 1), in Salta, Argentina [2]. ; at about 4,000 m. The main of this work was the isolation, sequencing and bioinformatic analysis of plasmid pAT23 from Halopiger sp. strain AT23, a haloarchaea isolated from living stromatolites. Plasmid DNA was isolated and sequenced by shotgun sequencing. DNA sequence of a novel plasmid pAT23 (7,843 bp) from haloarchaeal Halopiger sp. AT23 was determined. A total of 15 open reading frames (ORFs) were identified; putative functions were assigned to 4 of them among others with no annotatable function. One ORF was found with significant homology to the RepA of Haloarcula marismortui. Analysis of the nucleotide sequence also revealed the presence of type 1 fimbriae regulatory protein FimB as well as a protein pemK, responsible for mediating cell death through inhibiting protein synthesis through the cleavage of single-stranded RNA. The largest ORF encodes a putative RloA protein which shares homology with Lutiella nitroferrum. pAT23 is a novel plasmid isolated from the halophilic archaeon Halopiger sp. strain AT23, which has little homology with those haloarchaeal plasmids reported so far. To our knowledge this is the first report of the sequencing of a plasmid for the genus Halopiger.This work focuses on the molecular study of one plasmid in Archaea isolated from pristine high altitude wetlands in Argentina.