Glutamine synthesis in Streptomyces--a review

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Glutamine synthetase (GS) is crucial for ammonium assimilation in Streptomyces.
• GS synthesis and activity are regulated by nitrogen levels and post-translational modifications like adenylylation.

Purpose of the Study:

• To investigate the transcriptional regulation of GS synthesis in Streptomyces coelicolor.
• To identify the regulatory protein involved in nitrogen control of GS gene expression.

Main Methods:

• Analysis of GS gene (glnA) transcription in S. coelicolor.
• Characterization of the GlnR regulatory protein and its similarity to bacterial two-component systems.
• Cloning of GSII-like enzyme DNA from S. viridochromogenes and S. hygroscopicus.

Main Results:

• Nitrogen regulation of GS synthesis in S. coelicolor occurs at the transcriptional level.
• The GlnR protein acts as a positive regulator for glnA transcription.
• GlnR shares sequence homology with regulatory proteins from bacterial two-component systems.

Conclusions:

• GlnR is a key transcriptional regulator of GS synthesis in Streptomyces, functioning within a two-component regulatory system.
• The role of GSII isoenzymes in ammonium assimilation in Streptomyces requires further investigation.