4XDU

Crystal structure of Treponema pallidum TP0796 Flavin trafficking protein,a bifunctional FMN transferase/FAD pyrophosphatase, N55Y mutant, ADP bound form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.188 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.169 

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Ligand Structure Quality Assessment 


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Literature

Evidence for Posttranslational Protein Flavinylation in the Syphilis Spirochete Treponema pallidum: Structural and Biochemical Insights from the Catalytic Core of a Periplasmic Flavin-Trafficking Protein.

Deka, R.K.Brautigam, C.A.Liu, W.Z.Tomchick, D.R.Norgard, M.V.

(2015) mBio 6: e00519-e00515

  • DOI: https://doi.org/10.1128/mBio.00519-15
  • Primary Citation of Related Structures:  
    4XDR, 4XDT, 4XDU

  • PubMed Abstract: 

    The syphilis spirochete Treponema pallidum is an important human pathogen but a highly enigmatic bacterium that cannot be cultivated in vitro. T. pallidum lacks many biosynthetic pathways and therefore has evolved the capability to exploit host-derived metabolites via its periplasmic lipoprotein repertoire. We recently reported a flavin-trafficking protein in T. pallidum (Ftp_Tp; TP0796) as the first bacterial metal-dependent flavin adenine dinucleotide (FAD) pyrophosphatase that hydrolyzes FAD into AMP and flavin mononucleotide (FMN) in the spirochete's periplasm. However, orthologs of Ftp_Tp from other bacteria appear to lack this hydrolytic activity; rather, they bind and flavinylate subunits of a cytoplasmic membrane redox system (Nqr/Rnf). To further explore this dichotomy, biochemical analyses, protein crystallography, and structure-based mutagenesis were used to show that a single amino acid change (N55Y) in Ftp_Tp converts it from an Mg(2+)-dependent FAD pyrophosphatase to an FAD-binding protein. We also demonstrated that Ftp_Tp has a second enzymatic activity (Mg(2+)-FMN transferase); it flavinylates protein(s) covalently with FMN on a threonine side chain of an appropriate sequence motif using FAD as the substrate. Moreover, mutation of a metal-binding residue (D284A) eliminates Ftp_Tp's dual activities, thereby underscoring the role of Mg(2+) in the enzyme-catalyzed reactions. The posttranslational flavinylation activity that can target a periplasmic lipoprotein (TP0171) has not previously been described. The observed activities reveal the catalytic flexibility of a treponemal protein to perform multiple functions. Together, these findings imply mechanisms by which a dynamic pool of flavin cofactor is maintained and how flavoproteins are generated by Ftp_Tp locally in the T. pallidum periplasm. Treponema pallidum, the syphilis spirochete, exploits its periplasmic lipoproteins for a number of essential physiologic processes. One of these, flavin-trafficking protein (Ftp), not only exploits its catalytic center to mediate posttranslational flavinylation of proteins (to create flavoproteins) but also likely maintains the periplasmic flavin pool via its unique ability to hydrolyze FAD. This functional diversity within a single lipoprotein is quite remarkable and reflects the enzymatic versatility of the treponemal lipoproteins, as well as molecular parsimony in an organism with a limited genome. Ftp-mediated protein flavinylation in the periplasm also likely is a key aspect of a predicted flavin-dependent Rnf-based redox homeostasis system at the cytoplasmic membrane of T. pallidum. In addition to its importance in T. pallidum physiology, Ftp homologs exist in other bacteria, thereby expanding our understanding of the bacterial periplasm as a metabolically active subcellular compartment for flavoprotein biogenesis as well as flavin homeostasis.


  • Organizational Affiliation

    Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
FAD:protein FMN transferase340Treponema pallidum subsp. pallidum str. NicholsMutation(s): 1 
Gene Names: apbETP_0796
EC: 2.7.1.180
UniProt
Find proteins for O83774 (Treponema pallidum (strain Nichols))
Explore O83774 
Go to UniProtKB:  O83774
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO83774
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ADP
Query on ADP

Download Ideal Coordinates CCD File 
F [auth A]ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
EDO
Query on EDO

Download Ideal Coordinates CCD File 
G [auth A],
H [auth A],
I [auth A]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
ACT
Query on ACT

Download Ideal Coordinates CCD File 
J [auth A],
K [auth A]
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
MG
Query on MG

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
NA
Query on NA

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A]
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.188 
  • R-Value Work: 0.167 
  • R-Value Observed: 0.169 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 116.83α = 90
b = 46.814β = 102.22
c = 57.501γ = 90
Software Package:
Software NamePurpose
HKL-3000data reduction
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-3000data scaling
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-10-14
    Type: Initial release
  • Version 1.1: 2024-02-28
    Changes: Data collection, Database references, Derived calculations