5A5W

Crystal structure of Salmonella enterica HisA D7N D176A with ProFAR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.166 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Two-Step Ligand Binding in a Beta/Alpha8 Barrel Enzyme -Substrate-Bound Structures Shed New Light on the Catalytic Cycle of Hisa

Soderholm, A.Guo, X.Newton, M.S.Evans, G.B.Nasvall, J.Patrick, W.M.Selmer, M.

(2015) J.Biol.Chem. 290: 24657

  • DOI: 10.1074/jbc.M115.678086
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • HisA is a (βα)8 barrel enzyme that catalyzes the Amadori rearrangement of N'-[(5'-phosphoribosyl)formimino]-5-aminoimidazole-4-carboxamide ribonucleotide (ProFAR) to N'-((5'-phosphoribulosyl) formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide ( ...

    HisA is a (βα)8 barrel enzyme that catalyzes the Amadori rearrangement of N'-[(5'-phosphoribosyl)formimino]-5-aminoimidazole-4-carboxamide ribonucleotide (ProFAR) to N'-((5'-phosphoribulosyl) formimino)-5-aminoimidazole-4-carboxamide-ribonucleotide (PRFAR) in the histidine biosynthesis pathway, and it is a paradigm for the study of enzyme evolution. Still, its exact catalytic mechanism has remained unclear. Here, we present crystal structures of wild type Salmonella enterica HisA (SeHisA) in its apo-state and of mutants D7N and D7N/D176A in complex with two different conformations of the labile substrate ProFAR, which was structurally visualized for the first time. Site-directed mutagenesis and kinetics demonstrated that Asp-7 acts as the catalytic base, and Asp-176 acts as the catalytic acid. The SeHisA structures with ProFAR display two different states of the long loops on the catalytic face of the structure and demonstrate that initial binding of ProFAR to the active site is independent of loop interactions. When the long loops enclose the substrate, ProFAR adopts an extended conformation where its non-reacting half is in a product-like conformation. This change is associated with shifts in a hydrogen bond network including His-47, Asp-129, Thr-171, and Ser-202, all shown to be functionally important. The closed conformation structure is highly similar to the bifunctional HisA homologue PriA in complex with PRFAR, thus proving that structure and mechanism are conserved between HisA and PriA. This study clarifies the mechanistic cycle of HisA and provides a striking example of how an enzyme and its substrate can undergo coordinated conformational changes before catalysis.


    Organizational Affiliation

    the Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, 751 23 Uppsala, Sweden.,From the Department of Cell and Molecular Biology, Uppsala University, BMC, Box 596, 751 24 Uppsala, Sweden, maria.selmer@icm.uu.se.,the Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.,the Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand, wayne.patrick@otago.ac.nz.,the Ferrier Research Institute, Victoria University of Wellington, P.O. Box 33346, Petone, Lower Hutt 5046, New Zealand, and.,From the Department of Cell and Molecular Biology, Uppsala University, BMC, Box 596, 751 24 Uppsala, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
N/A
A
253Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 2 
Gene Names: hisA
EC: 5.3.1.16
Find proteins for P10372 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P10372
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GUO
Query on GUO

Download SDF File 
Download CCD File 
A
[(2R,3S,4R,5R)-5-[4-aminocarbonyl-5-[(E)-[[(2R,3R,4S,5R)-3,4-bis(oxidanyl)-5-(phosphonooxymethyl)oxolan-2-yl]amino]methylideneamino]imidazol-1-yl]-3,4-bis(oxidanyl)oxolan-2-yl]methyl dihydrogen phosphate
C15 H25 N5 O15 P2
QOUSHGMTBIIAHR-KEOHHSTQSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.166 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 46.607α = 90.00
b = 46.607β = 90.00
c = 197.949γ = 120.00
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling
PHASERphasing
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-09-02
    Type: Initial release
  • Version 1.1: 2015-10-21
    Type: Database references