1nut
From Proteopedia
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CRYSTAL STRUCTURE OF HUMAN CYTOSOLIC NMN/NaMN ADENYLYLTRANSFERASE COMPLEXED WITH ATP ANALOG
Overview
Pyridine dinucleotides (NAD and NADP) are ubiquitous cofactors involved in, hundreds of redox reactions essential for the energy transduction and, metabolism in all living cells. In addition, NAD also serves as a, substrate for ADP-ribosylation of a number of nuclear proteins, for silent, information regulator 2 (Sir2)-like histone deacetylase that is involved, in gene silencing regulation, and for cyclic ADP ribose (cADPR)-dependent, Ca(2+) signaling. Pyridine nucleotide adenylyltransferase (PNAT) is an, indispensable central enzyme in the NAD biosynthesis pathways catalyzing, the condensation of pyridine mononucleotide (NMN or NaMN) with the AMP, moiety of ATP to form NAD (or NaAD). Here we report the identification and, structural characterization of a novel human PNAT (hsPNAT-3) that is, located in the cytoplasm and mitochondria. Its subcellular localization, and tissue distribution are distinct from the previously identified human, nuclear PNAT-1 and PNAT-2. Detailed structural analysis of PNAT-3 in its, apo form and in complex with its substrate(s) or product revealed the, catalytic mechanism of the enzyme. The characterization of the cytosolic, human PNAT-3 provided compelling evidence that the final steps of NAD, biosynthesis pathways may exist in mammalian cytoplasm and mitochondria, potentially contributing to their NAD/NADP pool.
About this Structure
1NUT is a Single protein structure of sequence from Homo sapiens with SO4 and APC as ligands. Full crystallographic information is available from OCA.
Reference
Structural characterization of a human cytosolic NMN/NaMN adenylyltransferase and implication in human NAD biosynthesis., Zhang X, Kurnasov OV, Karthikeyan S, Grishin NV, Osterman AL, Zhang H, J Biol Chem. 2003 Apr 11;278(15):13503-11. Epub 2003 Feb 6. PMID:12574164
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