4IC5

Crystal structure of Deg5

Summary for 4IC5

• Entry DOI: 10.2210/pdb4ic5/pdb
• Related: 4IC5
• Descriptor: Protease Do-like 5, chloroplastic, CALCIUM ION (3 entities in total)
• Functional Keywords: bets-barrel, endopeptidase, calcium binding, chloroplast, hydrolase
• Biological source: Arabidopsis thaliana (mouse-ear cress,thale-cress)
• Cellular location: Plastid, chloroplast thylakoid lumen: Q9SEL7
• Total number of polymer chains: 3
• Total formula weight: 94667.51

Authors

Gong, W.,Sun, W.,Fan, H.,Gao, F.,Liu, L. (deposition date: 2012-12-10, release date: 2013-05-01, Last modification date: 2023-11-08)

Primary citation

Sun, W.,Gao, F.,Fan, H.,Shan, X.,Sun, R.,Liu, L.,Gong, W.
The structures of Arabidopsis Deg5 and Deg8 reveal new insights into HtrA proteases
Acta Crystallogr.,Sect.D, 69:830-837, 2013

PubMed 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.

PubMed: 23633592
DOI: 10.1107/S0907444913002023

Experimental method

X-RAY DIFFRACTION (2.607 Å)