1Z5N image
Entry Detail
PDB ID:
1Z5N
Keywords:
Title:
Crystal structure of MTA/AdoHcy nucleosidase Glu12Gln mutant complexed with 5-methylthioribose and adenine
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2005-03-18
Release Date:
2005-10-04
Method Details:
Experimental Method:
Resolution:
2.10 Å
R-Value Free:
0.25
R-Value Work:
0.20
R-Value Observed:
0.20
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:MTA/SAH nucleosidase
Mutations:E12Q
Chain IDs:A, B
Chain Length:242
Number of Molecules:2
Biological Source:Escherichia coli
Primary Citation
Structural snapshots of MTA/AdoHcy nucleosidase along the reaction coordinate provide insights into enzyme and nucleoside flexibility during catalysis
J.Mol.Biol. 352 559 574 (2005)
PMID: 16109423 DOI: 10.1016/j.jmb.2005.07.027

Abstact

MTA/AdoHcy nucleosidase (MTAN) irreversibly hydrolyzes the N9-C1' bond in the nucleosides, 5'-methylthioadenosine (MTA) and S-adenosylhomocysteine (AdoHcy) to form adenine and the corresponding thioribose. MTAN plays a vital role in metabolic pathways involving methionine recycling, biological methylation, polyamine biosynthesis, and quorum sensing. Crystal structures of a wild-type (WT) MTAN complexed with glycerol, and mutant-enzyme and mutant-product complexes have been determined at 2.0A, 2.0A, and 2.1A resolution, respectively. The WT MTAN-glycerol structure provides a purine-free model and in combination with the previously solved thioribose-free MTAN-ADE structure, we now have separate apo structures for both MTAN binding subsites. The purine and thioribose-free states reveal an extensive enzyme-immobilized water network in their respective binding subsites. The Asp197Asn MTAN-MTA and Glu12Gln MTAN-MTR.ADE structures are the first enzyme-substrate and enzyme-product complexes reported for MTAN, respectively. These structures provide representative snapshots along the reaction coordinate and allow insight into the conformational changes of the enzyme and the nucleoside substrate. A "catalytic movie" detailing substrate binding, catalysis, and product release is presented.

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