EVOLUTIONARY RESTRICTIONS IN THE SEDENTARY INTEGRON OF Pseudomonas punaustralis Ca10SN1

DANIELA CENTRON; FERNANDO MARTÍN ALONSO; MARIA PAULA QUIROGA

Congreso; Reunion Anual de Sociedades de Biociencias; 2020

Integrons are platforms of recombination and expression of genecassettes. Pseudomonas punaustralis Ca10SN1 is a recently discovered bacterium that carries a sedentary integron. In this work,we studied the distribution, structure, and recombinogenic characteristics of the attC sites of P. punaustralis Ca10SN1 to discuss theevolutionary role of its sedentary integron. For this, the P. punaustralis Ca10SN1 genome was sequenced, assembled and annotated.Integron related regions and their components were predicted usingIntegron finder. The dissemination of the P. punaustralis Ca10SN1attC sites was assessed using MegaBLAST, counting the number ofspecies whose hit was ≥97% of identity and coverage. The numberof mutations in the R and L boxes of the attC sites was estimatedby comparing them with the attC site associated with the integrase(IntIPpun). Secondary structures were obtained using the RNAfoldprogram of the Vienna RNA 2 package. Moreover, the probability ofattC sites of folding a recombinogenic structure (pfold) was calculated with previously published equations. One integron integrasewas predicted (IntIPpun), and 26 attC sites were identified, beingone attC site associated with IntIPpun, and 25 attC sites scatteredthroughout the genome in CALINs. Regarding dissemination, 50%of the predicted attC sites were unique of P. punaustralis Ca10SN1genome, 38.46% were exclusive to the genus Pseudomonas and7.7% were found outside the genus Pseudomonas. The mean mutations in the 1L, 2L, 2R, and 1R boxes were 2.16±0.21, 2.2±0.35,1.28±0.29, and 1.64±0.21bp, respectively. 2L and 2R showed significant differences (P