Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Standalone Viewers  
Protein Workshop | Ligand Explorer

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 27521.95 
• Atom Count: 1862 
• Residue Count: 241 
• Unique protein chains: 1

1H2H

Crystal structure of TM1643

• DOI: 10.2210/pdb1H2H/pdb

• Classification: STRUCTURAL GENOMICS UNKNOWN FUNCTION
• Organism(s): Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099)
• Expression System: Escherichia coli


• Deposited: 2002-08-08 Released: 2002-08-15 
• Deposition Author(s): Yang, Z., Savchenko, A., Edwards, A., Arrowsmith, C., Tong, L., Northeast Structural Genomics Consortium (NESG)

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.291 
• R-Value Work: 0.226 

Literature

Aspartate dehydrogenase, a novel enzyme identified from structural and functional studies of TM1643.

Yang, Z., Savchenko, A., Yakunin, A., Zhang, R., Edwards, A., Arrowsmith, C., Tong, L.

(2003) J. Biol. Chem. 278: 8804-8808

• PubMed: 12496312 
• DOI: 10.1074/jbc.M211892200


• PubMed Abstract: 
  

The open reading frame TM1643 of Thermotoga maritima belongs to a large family of proteins, with homologues in bacteria, archaea, and eukaryotes. TM1643 is found in an operon with two other genes that encode enzymes involved in the biosynthesis of NAD. In several bacteria, the gene in the position occupied by TM1643 encodes an aspartate oxidase (NadB), which synthesizes iminoaspartate as a substrate for NadA, the next enzyme in the pathway. The amino acid sequence of TM1643 does not share any recognizable homology with aspartate oxidase or with other proteins of known functions or structures. To help define the biological functions of TM1643, we determined its crystal structure at 2.6A resolution and performed a series of screens for enzymatic function. The structure reveals the presence of an N-terminal Rossmann fold domain with a bound NAD(+) cofactor and a C-terminal alpha+beta domain. The structural information suggests that TM1643 may be a dehydrogenase and the active site of the enzyme is located at the interface between the two domains. The enzymatic characterization of TM1643 revealed that it possesses NAD or NADP-dependent dehydrogenase activity toward l-aspartate but no aspartate oxidase activity. The product of the aspartate dehydrogenase activity is also iminoaspartate. Therefore, our studies demonstrate that two different enzymes, an oxidase and a dehydrogenase, may have evolved to catalyze the first step of NAD biosynthesis in prokaryotes. TM1643 establishes a new class of amino acid dehydrogenases.

---

Organizational Affiliation: 

Department of Biological Sciences, Columbia University, New York, New York 10027, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
HYPOTHETICAL PROTEIN TM1643	A	241	Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099)	Mutation(s): 0  Gene Names: nadX EC: 1.4.1.21
Find proteins for Q9X1X6 (Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099)) Go to UniProtKB:  Q9X1X6

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
NAD	A	NICOTINAMIDE-ADENINE-DINUCLEOTIDE C21 H27 N7 O14 P2 BAWFJGJZGIEFAR-NNYOXOHSSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.6 Å
• R-Value Free: 0.291 
• R-Value Work: 0.226 
• Space Group: P 4₁ 2₁ 2

Unit Cell:

Length (Å)	Angle (°)
a = 63.196	α = 90.00
b = 63.196	β = 90.00
c = 125.673	γ = 90.00

Software Package:

Software Name	Purpose
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling
SnB	phasing
SOLVE	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2002-08-08 
• Released Date: 2002-08-15 
• Deposition Author(s): Yang, Z., Savchenko, A., Edwards, A., Arrowsmith, C., Tong, L., Northeast Structural Genomics Consortium (NESG)

Revision History 

• Version 1.0: 2002-08-15
  Type: Initial release
• Version 1.1: 2015-04-29
  Type: Derived calculations, Non-polymer description, Other, Refinement description, Version format compliance
• Version 1.2: 2017-07-05
  Type: Refinement description
• Version 1.3: 2018-06-13
  Type: Data collection, Database references
• Version 1.4: 2019-08-21
  Type: Data collection, Database references, Derived calculations