7NA0

Structure of Geobacter sulfurreducens proline utilization A (PutA) variant A206W


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.170 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Probing the function of a ligand-modulated dynamic tunnel in bifunctional proline utilization A (PutA).

Korasick, D.A.Christgen, S.L.Qureshi, I.A.Becker, D.F.Tanner, J.J.

(2021) Arch Biochem Biophys 712: 109025-109025

  • DOI: https://doi.org/10.1016/j.abb.2021.109025
  • Primary Citation of Related Structures:  
    7NA0

  • PubMed Abstract: 

    In many bacteria, the reactions of proline catabolism are catalyzed by the bifunctional enzyme known as proline utilization A (PutA). PutA catalyzes the two-step oxidation of l-proline to l-glutamate using distinct proline dehydrogenase (PRODH) and l-glutamate-γ-semialdehyde dehydrogenase (GSALDH) active sites, which are separated by over 40 Å and connected by a complex tunnel system. The tunnel system consists of a main tunnel that connects the two active sites and functions in substrate channeling, plus six ancillary tunnels whose functions are unknown. Here we used tunnel-blocking mutagenesis to probe the role of a dynamic ancillary tunnel (tunnel 2a) whose shape is modulated by ligand binding to the PRODH active site. The 1.90 Å resolution crystal structure of Geobacter sulfurreducens PutA variant A206W verified that the side chain of Trp206 cleanly blocks tunnel 2a without perturbing the surrounding structure. Steady-state kinetic measurements indicate the mutation impaired PRODH activity without affecting the GSALDH activity. Single-turnover experiments corroborated a severe impairment of PRODH activity with flavin reduction decreased by nearly 600-fold in A206W relative to wild-type. Substrate channeling is also significantly impacted as A206W exhibited a 3000-fold lower catalytic efficiency in coupled PRODH-GSALDH activity assays, which measure NADH formation as a function of proline. The structure suggests that Trp206 inhibits binding of the substrate l-proline by preventing the formation of a conserved glutamate-arginine ion pair and closure of the PRODH active site. Our data are consistent with tunnel 2a serving as an open space through which the glutamate of the ion pair travels during the opening and closing of the active site in response to binding l-proline. These results confirm the essentiality of the conserved ion pair in binding l-proline and support the hypothesis that the ion pair functions as a gate that controls access to the PRODH active site.


  • Organizational Affiliation

    Department of Biochemistry, University of Missouri, Columbia, MO, 65211, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Bifunctional protein PutA
A, B
1,005Geobacter sulfurreducens PCAMutation(s): 1 
Gene Names: putAGSU3395
EC: 1.5.5.2 (PDB Primary Data), 1.2.1.88 (PDB Primary Data)
UniProt
Find proteins for Q746X3 (Geobacter sulfurreducens (strain ATCC 51573 / DSM 12127 / PCA))
Explore Q746X3 
Go to UniProtKB:  Q746X3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ746X3
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
FAD (Subject of Investigation/LOI)
Query on FAD

Download Ideal Coordinates CCD File 
C [auth A],
FA [auth B]
FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
SO4
Query on SO4

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A],
GA [auth B],
HA [auth B]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
EDO
Query on EDO

Download Ideal Coordinates CCD File 
AA [auth A]
AB [auth B]
BA [auth A]
BB [auth B]
CA [auth A]
AA [auth A],
AB [auth B],
BA [auth A],
BB [auth B],
CA [auth A],
CB [auth B],
DA [auth A],
DB [auth B],
EA [auth A],
EB [auth B],
F [auth A],
FB [auth B],
G [auth A],
H [auth A],
I [auth A],
IA [auth B],
J [auth A],
JA [auth B],
K [auth A],
KA [auth B],
L [auth A],
LA [auth B],
M [auth A],
MA [auth B],
N [auth A],
NA [auth B],
O [auth A],
OA [auth B],
P [auth A],
PA [auth B],
Q [auth A],
QA [auth B],
R [auth A],
RA [auth B],
S [auth A],
SA [auth B],
T [auth A],
TA [auth B],
U [auth A],
UA [auth B],
V [auth A],
VA [auth B],
W [auth A],
WA [auth B],
X [auth A],
XA [auth B],
Y [auth A],
YA [auth B],
Z [auth A],
ZA [auth B]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.199 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.170 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 95.418α = 90
b = 151.382β = 90
c = 175.553γ = 90
Software Package:
Software NamePurpose
Aimlessdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM065546

Revision History  (Full details and data files)

  • Version 1.0: 2021-09-22
    Type: Initial release
  • Version 1.1: 2021-09-29
    Changes: Database references
  • Version 1.2: 2023-10-18
    Changes: Data collection, Refinement description