6CK4 | pdb_00006ck4

G96A mutant of the PRPP riboswitch from T. mathranii bound to ppGpp


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Free: 
    0.304 (Depositor), 0.302 (DCC) 
  • R-Value Work: 
    0.248 (Depositor), 0.248 (DCC) 
  • R-Value Observed: 
    0.251 (Depositor) 

wwPDB Validation 3D Report Full Report

Validation slider image for 6CK4

Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history

Literature

Structures of two aptamers with differing ligand specificity reveal ruggedness in the functional landscape of RNA.

Knappenberger, A.J.Reiss, C.W.Strobel, S.A.

(2018) Elife 7

  • DOI: https://doi.org/10.7554/eLife.36381
  • Primary Citation Related Structures: 
    6CK4, 6CK5

  • PubMed Abstract: 

    Two classes of riboswitches related to the ykkC guanidine-I riboswitch bind phosphoribosyl pyrophosphate (PRPP) and guanosine tetraphosphate (ppGpp). Here we report the co-crystal structure of the PRPP aptamer and its ligand. We also report the structure of the G96A point mutant that prefers ppGpp over PRPP with a dramatic 40,000-fold switch in specificity. The ends of the aptamer form a helix that is not present in the guanidine aptamer and is involved in the expression platform. In the mutant, the base of ppGpp replaces G96 in three-dimensional space. This disrupts the S-turn, which is a primary structural feature of the ykkC RNA motif. These dramatic differences in ligand specificity are achieved with minimal mutations. ykkC aptamers are therefore a prime example of an RNA fold with a rugged fitness landscape. The ease with which the ykkC aptamer acquires new specificity represents a striking case of evolvability in RNA.


  • Organizational Affiliation
    • Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States.

Macromolecule Content 

  • Total Structure Weight: 155.11 kDa 
  • Atom Count: 9,041 
  • Modeled Residue Count: 418 
  • Deposited Residue Count: 468 
  • Unique nucleic acid chains: 1

Macromolecules

Find similar nucleic acids by:  (by identity cutoff) 
Entity ID: 1
MoleculeChains LengthOrganismImage
PRPP riboswitch
A, B, C, D
117Thermoanaerobacter mathranii
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
G4P
(Subject of Investigation/LOI)

Query on G4P



Download:Ideal Coordinates CCD File
KA [auth C],
R [auth A],
WA [auth D],
Z [auth B]
GUANOSINE-5',3'-TETRAPHOSPHATE
C10 H17 N5 O17 P4
BUFLLCUFNHESEH-UUOKFMHZSA-N
GTP

Query on GTP



Download:Ideal Coordinates CCD File
E [auth A]GUANOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O14 P3
XKMLYUALXHKNFT-UUOKFMHZSA-N
MPD

Query on MPD



Download:Ideal Coordinates CCD File
LA [auth C](4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
K

Query on K



Download:Ideal Coordinates CCD File
EA [auth C]
FA [auth C]
GA [auth C]
HA [auth C]
I [auth A]
EA [auth C],
FA [auth C],
GA [auth C],
HA [auth C],
I [auth A],
IA [auth C],
J [auth A],
JA [auth C],
K [auth A],
L [auth A],
M [auth A],
N [auth A],
O [auth A],
OA [auth D],
P [auth A],
PA [auth D],
Q [auth A],
QA [auth D],
RA [auth D],
SA [auth D],
TA [auth D],
UA [auth D],
V [auth B],
VA [auth D],
W [auth B],
X [auth B],
Y [auth B]
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
MG

Query on MG



Download:Ideal Coordinates CCD File
AA [auth C]
BA [auth C]
CA [auth C]
DA [auth C]
F [auth A]
AA [auth C],
BA [auth C],
CA [auth C],
DA [auth C],
F [auth A],
G [auth A],
H [auth A],
MA [auth D],
NA [auth D],
S [auth B],
T [auth B],
U [auth B]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.10 Å
  • R-Value Free:  0.304 (Depositor), 0.302 (DCC) 
  • R-Value Work:  0.248 (Depositor), 0.248 (DCC) 
  • R-Value Observed: 0.251 (Depositor) 
Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 53.252α = 91.18
b = 62.147β = 89.61
c = 125.909γ = 101.94
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PHASERphasing
PHENIXrefinement
REFMACrefinement
PDB_EXTRACTdata extraction
Cootmodel building
HKL-2000data scaling
HKL-2000data reduction

Structure Validation

View Full Validation Report



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 StatesGM022778

Revision History  (Full details and data files)

  • Version 1.0: 2018-06-20
    Type: Initial release
  • Version 1.1: 2019-02-20
    Changes: Advisory, Author supporting evidence, Data collection, Derived calculations
  • Version 1.2: 2020-01-01
    Changes: Author supporting evidence
  • Version 1.3: 2024-03-13
    Changes: Data collection, Database references, Derived calculations, Structure summary