English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Nitrogen metabolism plays a central role in the physiology of microorganisms, and Glutamine Synthetase (GS) genes are present in virtually all bacteria. In  M. tuberculosis , four GS genes are present, but only  glnA1  is essential, whereas  glnA2  was shown to be non-essential for  in-vitro  as well as  in-vivo  growth and pathogenesis, and is postulated to be involved in D-glutamine and iso-glutamine synthesis. Whilst investigating the activity of an antimicrobial compound in  M. smegmatis , we found a spontaneous temperature-sensitive mutant in  glnA2  (I133F), and used it to investigate the role of  glnA2  in  M. smegmatis . We deleted the native  glnA2  and replaced it with a mutated allele. This re-created the temperature sensitivity—as after 3–4 seemingly normal division cycles,  glnA2  became essential for growth. This essentiality could not be salvaged by neither L, D- nor iso-glutamine, suggesting an additional role of  glnA2  in  M. smegmatis  over its role in  M. tuberculosis . We also found that overexpression of the global nitrogen regulator  glnR  enabled bypassing the essentiality of  glnA2 , allowing the creation of a complete deletion mutant. The discrepancy between the importance of  glnA2  in Mtb and  M. smegmatis  stresses the caution in which results in one are extrapolated to the other.

frontiers in microbiology

The Unexpected Essentiality of glnA2 in Mycobacterium smegmatis Is Salvaged by Overexpression of the Global Nitrogen Regulator glnR, but Not by L-, D- or Iso-Glutamine