Serine/Threonine phosphatase Z1 (Candida albicans) binds to inhibitor microcystin-LR

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.182 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report

This is version 2.0 of the entry. See complete history


Molecular Insights into the Fungus-Specific Serine/Threonine Protein Phosphatase Z1 in Candida albicans.

Chen, E.Choy, M.S.Petrenyi, K.Konya, Z.Erdodi, F.Dombradi, V.Peti, W.Page, R.

(2016) mBio 7

  • DOI: https://doi.org/10.1128/mBio.00872-16
  • Primary Citation of Related Structures:  
    5JPE, 5JPF

  • PubMed Abstract: 

    The opportunistic pathogen Candida is one of the most common causes of nosocomial bloodstream infections. Because candidemia is associated with high mortality rates and because the incidences of multidrug-resistant Candida are increasing, efforts to identify novel targets for the development of potent antifungals are warranted. Here, we describe the structure and function of the first member of a family of protein phosphatases that is specific to fungi, protein phosphatase Z1 (PPZ1) from Candida albicans We show that PPZ1 not only is active but also is as susceptible to inhibition by the cyclic peptide inhibitor microcystin-LR as its most similar human homolog, protein phosphatase 1α (PP1α [GLC7 in the yeast Saccharomyces cerevisiae]). Unexpectedly, we also discovered that, despite its 66% sequence identity to PP1α, the catalytic domain of PPZ1 contains novel structural elements that are not present in PP1α. We then used activity and pulldown assays to show that these structural differences block a large subset of PP1/GLC7 regulatory proteins from effectively binding PPZ1, demonstrating that PPZ1 does not compete with GLC7 for its regulatory proteins. Equally important, these unique structural elements provide new pockets suitable for the development of PPZ1-specific inhibitors. Together, these studies not only reveal why PPZ1 does not negatively impact GLC7 activity in vivo but also demonstrate that the family of fungus-specific phosphatases-especially PPZ1 from C. albicans-are highly suitable targets for the development of novel drugs that specifically target C. albicans without cross-reacting with human phosphatases. Candida albicans is a medically important human pathogen that is the most common cause of fungal infections in humans. In particular, approximately 46,000 cases of health care-associated candidiasis occur each year in the United States. Because these infections are associated with high mortality rates and because multiple species of Candida are becoming increasingly resistant to antifungals, there are increasing efforts to identify novel targets that are essential for C. albicans virulence. Here we use structural and biochemical approaches to elucidate how a member of a fungus-specific family of enzymes, serine/threonine phosphatase PPZ1, functions in C. albicans We discovered multiple unique features of PPZ1 that explain why it does not cross-react with, and in turn compete for, PP1-specific regulators, a long-standing question in the field. Most importantly, however, these unique features identified PPZ1 as a potential target for the development of novel antifungal therapeutics that will provide new, safe, and potent treatments for candidiasis in humans.

  • Organizational Affiliation

    Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serine/threonine-protein phosphatase317Candida albicansMutation(s): 0 
Gene Names: CAWG_01946
Find proteins for C4YM68 (Candida albicans (strain WO-1))
Explore C4YM68 
Go to UniProtKB:  C4YM68
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupC4YM68
Sequence Annotations
  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Microcystin-LRB [auth M]7Microcystis aeruginosaMutation(s): 0 
Sequence Annotations
  • Reference Sequence
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.182 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 50.665α = 90
b = 50.665β = 90
c = 201.054γ = 120
Software Package:
Software NamePurpose
HKL-2000data scaling
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM098482

Revision History  (Full details and data files)

  • Version 1.0: 2016-08-31
    Type: Initial release
  • Version 1.1: 2016-09-07
    Changes: Database references
  • Version 1.2: 2017-09-13
    Changes: Advisory, Author supporting evidence, Derived calculations
  • Version 1.3: 2019-12-25
    Changes: Author supporting evidence
  • Version 1.4: 2023-09-27
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 2.0: 2023-11-15
    Changes: Atomic model, Data collection, Derived calculations