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| Author(s): |
Nicolas Federico Villamil Munevar
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2015-08-06 |
| Examining board members: |
Beny Spira;
Regina Lúcia Baldini;
Teca Calcagno Galvao
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| Advisor: | Beny Spira |
| Abstract | |
The pst operon in P. aeruginosa encodes a high-affinity phosphate transporter and the PhoU protein, which together act as repressors of Pho regulon of this species. The PhoU activity is also related with polyphosphate (polyP) metabolism, since phoU null mutants have a large accumulation of the biopolymer. β-galactosidase assays allowed to confirm a change in the expression of ppk and ppx genes, in-volved in PolyP metabolism, in the phoU mutant. It was also evidenced that in the wild type strain, the ppk and ppx transcription does not respond to Pi or nitrogen starvation, and that these genes are highly expressed under conditions of normal growth. In addition, it was determined that ppk is co-transcribed with hemB, a gene involved in the synthesis of porphyrins, and they constitute therefore an operon. The pst operon was also examined. Was identified by northern blot the transcript of the first gene in the operon, pstS, which encodes a periplasmic protein. Also, a promoter was identified immediately upstream of phoU, the most distal gene in the operon, allowing its expression in normal conditions of bacterial growth. Finally, it was determined by EMSA that the two consensus sequences Pho box present in the pst operon are fully functional. (AU) | |
| FAPESP's process: | 12/11537-2 - The relation between polyphosphate metabolism and the pst and pit genes of P. aeruginosa |
| Grantee: | Nicolas Federico Villamil Munevar |
| Support Opportunities: | Scholarships in Brazil - Master |