3dla

Publication Abstract from PubMed

NAD(+) is an essential metabolite both as a cofactor in energy metabolism and redox homeostasis and as a regulator of cellular processes. In contrast to humans, Mycobacterium tuberculosis NAD(+) biosynthesis is absolutely dependent on the activity of a multifunctional glutamine-dependent NAD(+) synthetase, which catalyzes the ATP-dependent formation of NAD(+) at the synthetase domain using ammonia derived from L-glutamine in the glutaminase domain. Here we report the kinetics and structural characterization of M. tuberculosis NAD(+) synthetase. The kinetics data strongly suggest tightly coupled regulation of the catalytic activities. The structure, the first of a glutamine-dependent NAD(+) synthetase, reveals a homooctameric subunit organization suggesting a tight dependence of catalysis on the quaternary structure, a 40-A intersubunit ammonia tunnel and structural elements that may be involved in the transfer of information between catalytic sites.

Regulation of active site coupling in glutamine-dependent NAD(+) synthetase.,LaRonde-LeBlanc N, Resto M, Gerratana B Nat Struct Mol Biol. 2009 Apr;16(4):421-9. Epub 2009 Mar 8. PMID:19270703^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.