3NM4: Helicobacter Pylori Mtan

The bacterial enzyme 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) plays a central role in three essential metabolic pathways in bacteria: methionine salvage, purine salvage, and polyamine biosynthesis. Recently, its role in the pathway that leads to the production of autoinducer II, an important component in quorum-sensing, has garnered much interest. Because of this variety of roles, MTAN is an attractive target for developing new classes of inhibitors that influence bacterial virulence and biofilm formation. To gain insight toward the development of new classes of MTAN inhibitors, the interactions between the Helicobacter pylori-encoded MTAN and its substrates and substrate analogs were probed using X-ray crystallography. The structures of MTAN, an MTAN-Formycin A complex, and an adenine bound form were solved by molecular replacement and refined to 1.7, 1.8, and 1.6 A, respectively. The ribose-binding site in the MTAN and MTAN-adenine cocrystal structures contain a tris[hydroxymethyl]aminomethane molecule that stabilizes the closed form of the enzyme and displaces a nucleophilic water molecule necessary for catalysis. This research gives insight to the interactions between MTAN and bound ligands that promote closing of the enzyme active site and highlights the potential for designing new classes of MTAN inhibitors using a link/grow or ligand assembly development strategy based on the described H. pylori MTAN crystal structures.
PDB ID: 3NM4Download
MMDB ID: 86465
PDB Deposition Date: 2010/6/21
Updated in MMDB: 2010/12
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 3NM4: dimeric; determined by author and by software (PISA)
Molecular Components in 3NM4
Label Count Molecule
Proteins (2 molecules)
Mta/sah Nucleosidase
Molecule annotation
Chemicals (7 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB