6KZB

Transglutaminase2 complexed with calcium


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.55 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.227 

wwPDB Validation   3D Report Full Report


This is version 1.0 of the entry. See complete history


Literature

Competitive Binding of Magnesium to Calcium Binding Sites Reciprocally Regulates Transamidase and GTP Hydrolysis Activity of Transglutaminase 2.

Jeong, E.M.Lee, K.B.Kim, G.E.Kim, C.M.Lee, J.H.Kim, H.J.Shin, J.W.Kwon, M.A.Park, H.H.Kim, I.G.

(2020) Int J Mol Sci 21

  • DOI: 10.3390/ijms21030791
  • Primary Citation of Related Structures:  
    6KZB

  • PubMed Abstract: 
  • Transglutaminase 2 (TG2) is a Ca 2+ -dependent enzyme, which regulates various cellular processes by catalyzing protein crosslinking or polyamination. Intracellular TG2 is activated and inhibited by Ca 2+ and GTP binding, respectively ...

    Transglutaminase 2 (TG2) is a Ca 2+ -dependent enzyme, which regulates various cellular processes by catalyzing protein crosslinking or polyamination. Intracellular TG2 is activated and inhibited by Ca 2+ and GTP binding, respectively. Although aberrant TG2 activation has been implicated in the pathogenesis of diverse diseases, including cancer and degenerative and fibrotic diseases, the structural basis for the regulation of TG2 by Ca 2+ and GTP binding is not fully understood. Here, we produced and analyzed a Ca 2+ -containing TG2 crystal, and identified two glutamate residues, E437 and E539, as Ca 2+ -binding sites. The enzymatic analysis of the mutants revealed that Ca 2+ binding to these sites is required for the transamidase activity of TG2. Interestingly, we found that magnesium (Mg 2+ ) competitively binds to the E437 and E539 residues. The Mg 2+ binding to these allosteric sites enhances the GTP binding/hydrolysis activity but inhibits transamidase activity. Furthermore, HEK293 cells transfected with mutant TG2 exhibited higher transamidase activity than cells with wild-type TG2. Cells with wild-type TG2 showed an increase in transamidase activity under Mg 2+ -depleted conditions, whereas cells with mutant TG2 were unaffected. These results indicate that E437 and E539 are Ca 2+ -binding sites contributing to the reciprocal regulation of transamidase and GTP binding/hydrolysis activities of TG2 through competitive Mg 2+ binding.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Korea.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein-glutamine gamma-glutamyltransferase 2 ABC687Homo sapiensMutation(s): 0 
Gene Names: TGM2
EC: 2.3.2.13
Find proteins for P21980 (Homo sapiens)
Explore P21980 
Go to UniProtKB:  P21980
NIH Common Fund Data Resources
PHAROS:  P21980
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.55 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.227 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 133.08α = 90
b = 216.307β = 90
c = 166.263γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data collection
HKL-2000data scaling
PHASERphasing
Cootmodel building

Structure Validation

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Entry History & Funding Information

Deposition Data

  • Deposited Date: 2019-09-23 
  • Released Date: 2020-12-09 
  • Deposition Author(s): Park, H.H., Kim, C.M.

Funding OrganizationLocationGrant Number
National Research Foundation (NRF, Korea)Korea, Republic Of--

Revision History  (Full details and data files)

  • Version 1.0: 2020-12-09
    Type: Initial release