Journal of Undergraduate Research
Keywords
Phob, mutations, phosphate regulation, PhoA, PhoB, PhoR
College
Life Sciences
Department
Microbiology and Molecular Biology
Abstract
Within the prokaryotic cell, the intake of essential nutrients is continuously regulated by intracellular mechanisms. When fundamental nutrients become scarce, cellular stress responses are activated to enable the cell to survive in a harsh environment. Recent studies have shown a two-component regulatory mechanism which enhances Escherichia coli intracellular phosphate uptake in a phosphatepoor environment (5). This system, called the Pho system, consists of a sensor (PhoR) and an activator (PhoB). When environmental phosphate is limited, PhoR becomes autophosphorylated and in turn phosphorylates PhoB (4). The phosphorylated PhoB recognizes and binds to a consensus sequence called the “pho box” and transcription of phosphate uptake and processing genes is enhanced (2). PhoA, or alkaline phosphatase (AP), is an enzyme produced by one of these genes; intracellular levels of PhoA increase as phosphate concentrations decrease in the cellular environment (3). PhoA cleaves bound phosphate in the periplasmic (outer) space of the cell so that it can be transported into the cytoplasm, or inner area of the cell.
Recommended Citation
Lowe, Chad C. and McCleary, Dr. William R.
(2014)
"Random Mutagenesis in Phob: a Proposed Study of The Effects of Mutations in Phosphate Regulation,"
Journal of Undergraduate Research: Vol. 2014:
Iss.
1, Article 802.
Available at:
https://scholarsarchive.byu.edu/jur/vol2014/iss1/802