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

NAD +  synthetase is an essential enzyme of de novo and recycling pathways of NAD +  biosynthesis in  Mycobacterium tuberculosis  but not in humans. This bifunctional enzyme couples the NAD +  synthetase and glutaminase activities through an ammonia tunnel but free ammonia is also a substrate. Here we show that the  Homo sapiens  NAD +  synthetase (hsNadE) lacks substrate specificity for glutamine over ammonia and displays a modest activation of the glutaminase domain compared to tbNadE. We report the crystal structures of hsNadE and NAD +  synthetase from  M. tuberculosis  (tbNadE) with synthetase intermediate analogues. Based on the observed exclusive arrangements of the domains and of the intra- or inter-subunit tunnels we propose a model for the inter-domain communication mechanism for the regulation of glutamine-dependent activity and NH 3  transport. The structural and mechanistic comparison herein reported between hsNadE and tbNadE provides also a starting point for future efforts in the development of anti-TB drugs.

Different ways to transport ammonia in human and Mycobacterium tuberculosis NAD+ synthetases