1CB0

STRUCTURE OF HUMAN 5'-DEOXY-5'-METHYLTHIOADENOSINE PHOSPHORYLASE AT 1.7 A RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.181 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The structure of human 5'-deoxy-5'-methylthioadenosine phosphorylase at 1.7 A resolution provides insights into substrate binding and catalysis.

Appleby, T.C.Erion, M.D.Ealick, S.E.

(1999) Structure 7: 629-641

  • DOI: https://doi.org/10.1016/s0969-2126(99)80084-7
  • Primary Citation of Related Structures:  
    1CB0, 1CG6

  • PubMed Abstract: 

    5'-Deoxy-5'-methylthioadenosine phosphorylase (MTAP) catalyzes the reversible phosphorolysis of 5'-deoxy-5'-methylthioadenosine (MTA) to adenine and 5-methylthio-D-ribose-1-phosphate. MTA is a by-product of polyamine biosynthesis, which is essential for cell growth and proliferation. This salvage reaction is the principle source of free adenine in human cells. Because of its importance in coupling the purine salvage pathway to polyamine biosynthesis MTAP is a potential chemotherapeutic target. We have determined the crystal structure of MTAP at 1.7 A resolution using multiwavelength anomalous diffraction phasing techniques. MTAP is a trimer comprised of three identical subunits. Each subunit consists of a single alpha/beta domain containing a central eight-stranded mixed beta sheet, a smaller five-stranded mixed beta sheet and six alpha helices. The native structure revealed the presence of an adenine molecule in the purine-binding site. The structure of MTAP with methylthioadenosine and sulfate ion soaked into the active site was also determined using diffraction data to 1.7 A resolution. The overall quaternary structure and subunit topology of MTAP are similar to mammalian purine nucleoside phosphorylase (PNP). The structures of the MTAP-ligand complexes provide a map of the active site and suggest possible roles for specific residues in substrate binding and catalysis. Residues accounting for the differences in substrate specificity between MTAP and PNP are also identified. Detailed information about the structure and chemical nature of the MTAP active site will aid in the rational design of inhibitors of this potential chemotherapeutic target. The MTAP structure represents the first structure of a mammalian PNP that is specific for 6-aminopurines.


  • Organizational Affiliation

    Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (5'-DEOXY-5'-METHYLTHIOADENOSINE PHOSPHORYLASE)283Homo sapiensMutation(s): 1 
EC: 2.4.2.28
UniProt & NIH Common Fund Data Resources
Find proteins for Q13126 (Homo sapiens)
Explore Q13126 
Go to UniProtKB:  Q13126
PHAROS:  Q13126
GTEx:  ENSG00000099810 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ13126
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ADE
Query on ADE

Download Ideal Coordinates CCD File 
B [auth A]ADENINE
C5 H5 N5
GFFGJBXGBJISGV-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.181 
  • Space Group: P 3 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 120.76α = 90
b = 120.76β = 90
c = 44.46γ = 120
Software Package:
Software NamePurpose
MADSYSphasing
SHELXmodel building
MLPHAREphasing
X-PLORrefinement
MOSFLMdata reduction
CCP4data scaling
SHELXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1999-07-05
    Type: Initial release
  • Version 1.1: 2008-04-26
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2023-12-27
    Changes: Data collection, Database references, Derived calculations