title: Crystal structures of E. coli nicotinate mononucleotide adenylyltransferase and its complex with deamido-NAD.
abstract: Nicotinamide/Nicotinate mononucleotide (NMN/NaMN) adenylyltransferase is an indispensable enzyme in both de novo biosynthesis and salvage of NAD+ and NADP+. In prokaryotes, it is absolutely required for cell survival, thus representing an attractive target for the development of new broad-spectrum antibacteria inhibitors. The crystal structures of E. coli NaMN adenylyltransferase (NMNAT) and its complex with deamido-NAD (NaAD) revealed that ligand binding causes large conformational changes in several loop regions around the active site. The enzyme specifically recognizes the deamidated pyridine nucleotide through interactions between nicotinate carboxylate with several protein main chain amides and a positive helix dipole. Comparison of E. coli NMNAT with those from archaeal organisms revealed extensive differences in the active site architecture, enzyme-ligand interaction mode, and bound dinucleotide conformations. The bacterial NaMN adenylyltransferase structures described here provide a foundation for structure-based design of specific inhibitors that may have therapeutic potential.
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA. zhang@chop.swmed.edu
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Tianjun
authors.initials: T
authors.lastname: Zhou
authors.forename: Oleg
authors.initials: O
authors.lastname: Kurnasov
authors.forename: Sara
authors.initials: S
authors.lastname: Cheek
authors.forename: Nick V
authors.initials: NV
authors.lastname: Grishin
authors.forename: Andrei
authors.initials: A
authors.lastname: Osterman
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009243:NAD / Q000031:analogs & derivatives* / Q000378:metabolism*; D009612:Nicotinamide-Nucleotide Adenylyltransferase; D009713:Nucleotidyltransferases / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
chemical_list: D019843:Archaeal Proteins; D009243:NAD; C018348:nicotinic acid adenine dinucleotide; D009713:Nucleotidyltransferases; D009612:Nicotinamide-Nucleotide Adenylyltransferase; C038480:nicotinic acid mononucleotide adenylyltransferase