Biochemical characterization and posttranslational modification of AlgU, a regulator of stress response in Pseudomonas aeruginosa.

Abstract

AlgU is homologous to the extreme heat shock sigma factor sigma E from enteric bacteria. In this work, AlgU was overproduced and purified and its function investigated at the biochemical level. AlgU was shown to associate with RNA polymerase and direct transcription of a target promoter. AlgU also exhibited multiple isoforms detected by 2D gel analysis. Treatment with a Ser/Thr phosphatase shifted the distribution of isoforms towards the basic side on 2D gels, suggesting that posttranslational modifications of AlgU may involve phosphorylation. The underphosphorylated forms of AlgU copurified with RNA polymerase. It is possible that phosphorylation affects AlgU activity or its stability.

• Authors: M J Schurr, H Yu, J M Martinez-Salazar, N S Hibler, V Deretic
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 216 Issue 3 Pg. 874-80 (Nov 22 1995) ISSN: 0006-291X [Print] United States
• PMID: 7488207 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• AlgU protein, Pseudomonas aeruginosa
• Bacterial Proteins
• Recombinant Fusion Proteins
• Sigma Factor
• Sulfur Radioisotopes
• DNA-Directed RNA Polymerases

Topics

• Amino Acid Sequence
• Bacterial Proteins (genetics, isolation & purification, metabolism)
• Chemical Precipitation
• DNA-Directed RNA Polymerases (metabolism)
• Electrophoresis, Gel, Two-Dimensional
• Escherichia coli (enzymology)
• Isotope Labeling
• Molecular Sequence Data
• Phosphorylation
• Protein Processing, Post-Translational
• Pseudomonas aeruginosa (chemistry)
• Recombinant Fusion Proteins (metabolism)
• Sigma Factor
• Sulfur Radioisotopes
• Transcription, Genetic