5CCE

Joint X-ray/neutron structure of wild type MTAN complexed with SRH and adenine


Experimental Data Snapshot

  • Method: NEUTRON DIFFRACTION

  • Method: X-RAY DIFFRACTION

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Neutron structures of the Helicobacter pylori 5'-methylthioadenosine nucleosidase highlight proton sharing and protonation states.

Banco, M.T.Mishra, V.Ostermann, A.Schrader, T.E.Evans, G.B.Kovalevsky, A.Ronning, D.R.

(2016) Proc Natl Acad Sci U S A 113: 13756-13761

  • DOI: https://doi.org/10.1073/pnas.1609718113
  • Primary Citation of Related Structures:  
    5CCD, 5CCE, 5JPC, 5K1Z, 5KB3

  • PubMed Abstract: 

    MTAN (5'-methylthioadenosine nucleosidase) catalyzes the hydrolysis of the N-ribosidic bond of a variety of adenosine-containing metabolites. The Helicobacter pylori MTAN (HpMTAN) hydrolyzes 6-amino-6-deoxyfutalosine in the second step of the alternative menaquinone biosynthetic pathway. Substrate binding of the adenine moiety is mediated almost exclusively by hydrogen bonds, and the proposed catalytic mechanism requires multiple proton-transfer events. Of particular interest is the protonation state of residue D198, which possesses a pK a above 8 and functions as a general acid to initiate the enzymatic reaction. In this study we present three corefined neutron/X-ray crystal structures of wild-type HpMTAN cocrystallized with S-adenosylhomocysteine (SAH), Formycin A (FMA), and (3R,4S)-4-(4-Chlorophenylthiomethyl)-1-[(9-deaza-adenin-9-yl)methyl]-3-hydroxypyrrolidine (p-ClPh-Thio-DADMe-ImmA) as well as one neutron/X-ray crystal structure of an inactive variant (HpMTAN-D198N) cocrystallized with SAH. These results support a mechanism of D198 pKa elevation through the unexpected sharing of a proton with atom N7 of the adenine moiety possessing unconventional hydrogen-bond geometry. Additionally, the neutron structures also highlight active site features that promote the stabilization of the transition state and slight variations in these interactions that result in 100-fold difference in binding affinities between the DADMe-ImmA and ImmA analogs.


  • Organizational Affiliation

    Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
5'-Methylthioadenosine Nucleosidase230Helicobacter pyloriMutation(s): 0 
Gene Names: mtnNmtnjhp_0082
EC: 3.2.2.30 (PDB Primary Data), 3.2.2.9 (PDB Primary Data)
UniProt
Find proteins for Q9ZMY2 (Helicobacter pylori (strain J99 / ATCC 700824))
Explore Q9ZMY2 
Go to UniProtKB:  Q9ZMY2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9ZMY2
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
2WP
Query on 2WP

Download Ideal Coordinates CCD File 
B [auth A]S-ribosylhomocysteine
C9 H17 N O6 S
IQFWYNFDWRYSRA-LYNCRYNASA-N
ADE
Query on ADE

Download Ideal Coordinates CCD File 
C [auth A]ADENINE
C5 H5 N5
GFFGJBXGBJISGV-UHFFFAOYSA-N
D8U
Query on D8U

Download Ideal Coordinates CCD File 
D [auth A]deuterium(1+)
D
GPRLSGONYQIRFK-DYCDLGHISA-N
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.189α = 90
b = 83.189β = 90
c = 67.633γ = 120
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata processing
SCALEPACKdata scaling
HKL-3000data processing
Cootmodel building
Omodel building
nCNSrefinement

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Aeronautic Space Administration (NASA, United States)United StatesN-123528-01

Revision History  (Full details and data files)

  • Version 1.0: 2016-11-16
    Type: Initial release
  • Version 1.1: 2016-12-21
    Changes: Database references
  • Version 1.2: 2020-01-01
    Changes: Author supporting evidence
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2023-09-27
    Changes: Data collection, Database references, Refinement description, Structure summary