Selection and identification of PHO-constitutive mutations in the pst operon

• Grant number: 12/16580-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2013
• End date: December 31, 2013
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal Investigator: Beny Spira
• Grantee: Livia Akemi Moracima
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The pst operon (or pstSCAB-Phou) E. coli belong to the pho regulon, which in turn responds to external stimulus limitation phosphate (Pi). Pst the genes coding for a transport system Pi of high affinity, which also acts as a repressor of pho regulon capable of the abundance of Pi in the middle. In this design will be isolated pst spontaneous mutants in a culture medium containing glycerol 2-phosphate (G2P) as the sole carbon source. The presence of the G2P means has a selective pressure to relieve the repression excess Pi pho regulon exerts on, resulting in changes in pst. These changes are adaptive, ie, arise only when in contact with the substrate G2P. The adaptive mechanism that causes mutations is not clear. In order to characterize these mutants, a few dozen of these mutations will be identified and sequenced. (AU)