Acta Crystallographica Section D

Biological Crystallography

Volume 69, Part 5 (May 2013)


research papers



Acta Cryst. (2013). D69, 830-837    [ doi:10.1107/S0907444913002023 ]

The structures of Arabidopsis Deg5 and Deg8 reveal new insights into HtrA proteases

W. Sun, F. Gao, H. Fan, X. Shan, R. Sun, L. Liu and W. Gong

Abstract: Plant Deg5 and Deg8 are two members of the HtrA proteases, a family of oligomeric serine endopeptidases that are involved in a variety of protein quality-control processes. These two HtrA proteases are located in the thylakoid lumen and participate in high-light stress responses by collaborating with other chloroplast proteins. Deg5 and Deg8 degrade photodamaged D1 protein of the photosystem II reaction centre, allowing its in situ replacement. Here, the crystal structures of Arabidopsis thaliana Deg5 (S266A) and Deg8 (S292A) are reported at 2.6 and 2.0 Å resolution, respectively. The Deg5 trimer contains two calcium ions in a central channel, suggesting a link between photodamage control and calcium ions in chloroplasts. Previous structures of HtrA proteases have indicated that their regulation usually requires C-terminal PDZ domain(s). Deg5 is unique in that it contains no PDZ domain and the trimeric structure of Deg5 (S266A) reveals a novel catalytic triad conformation. A similar triad conformation is observed in the hexameric structure of the single PDZ-domain-containing Deg8 (S292A). These findings suggest a novel activation mechanism for plant HtrA proteases and provide structural clues to their function in light-stress response.

PDB references: 4ic5 and 4ic6

Keywords: protease-chaperones; protein quality control; PDZ domains; oligomerization.


pdfdisplay filedownload file

Portable Document Format (PDF) file
[ doi:10.1107/S0907444913002023/dw5040sup1.pdf ]
Supplementary material


Notes:

To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.

The download button will force most browsers to prompt for a file name to store the data on your hard disk.

Where possible, images are represented by thumbnails.

 bibliographic record in  format

  Find reference:   Volume   Page   
  Search:     From   to      Advanced search

Copyright © International Union of Crystallography
IUCr Webmaster