PDBsum entry 5ilb

Hydrolase

PDB id: 5ilb

Contents

Protein chains

466 a.a.

Waters ×1045

PDB id:

5ilb

Name:

Hydrolase

Title:

Crystal structure of protease domain of deg2 linked with the pdz domain of deg9

Structure:

Protease do-like 2, chloroplastic,protease do-like 9. Chain: a, b. Engineered: yes. Other_details: fusion protein of protease domain of deg2 (residues 110-315 of o82261, degp2_arath) and the pdz domain of deg9 (residues 326-592 of q9fl12 degp9_arath).

Source:

Arabidopsis thaliana. Mouse-ear cress. Organism_taxid: 3702. Gene: degp2, at2g47940, f17a22.33, t9j23.7, degp9, at5g40200, msn9.10, msn9.100. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.85Å R-factor: 0.191 R-free: 0.225

Authors:

M.Ouyang,L.Liu,X.Y.Li,S.Zhao,L.X.Zhang

Key ref:

M.Ouyang et al. (2017). The crystal structure of Deg9 reveals a novel octameric-type HtrA protease. Nat Plants, 3, 973-982. PubMed id: 29180814 DOI: 10.1038/s41477-017-0060-2

Date:

04-Mar-16 Release date: 08-Mar-17

Protein chains

O82261  (DEGP2_ARATH) -  Protease Do-like 2, chloroplastic from Arabidopsis thaliana

Seq: 607 a.a.

Struc: 466 a.a.*

Protein chains

Q9FL12  (DEGP9_ARATH) -  Protease Do-like 9 from Arabidopsis thaliana

Seq: 592 a.a.

Struc: 466 a.a.*

* PDB and UniProt seqs differ at 224 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.4.21.- - ?????

DOI no: 10.1038/s41477-017-0060-2

Nat Plants 3:973-982 (2017)

PubMed id: 29180814

The crystal structure of Deg9 reveals a novel octameric-type HtrA protease.

M.Ouyang, X.Li, S.Zhao, H.Pu, J.Shen, Z.Adam, T.Clausen, L.Zhang.

ABSTRACT

The high temperature requirement A (HtrA) proteases (also termed Deg proteases) play important roles in diverse organisms by regulating protein quality and quantity. One of the 16 Arabidopsis homologs, Deg9, is located in the nucleus where it modulates cytokinin- and light-mediated signalling via degrading the ARABIDOPSIS RESPONSE REGULATOR 4 (ARR4). To uncover the structural features underlying the proteolytic activity of Deg9, we determined its crystal structure. Unlike the well-established trimeric building block of HtrAs, Deg9 displays a novel octameric structure consisting of two tetrameric rings that have distinct conformations. Based on the structural architecture, we generated several mutant variants of Deg9, determined their structure and tested their proteolytic activity towards ARR4. The results of the structural and biochemical analyses allowed us to propose a model for a novel mechanism of substrate recognition and activity regulation of Deg9. In this model, protease activation of one tetramer is mediated by en-bloc reorientation of the protease domains to open an entrance for the substrate in the opposite (inactive) tetramer. This study provides the structural basis for understanding how the levels of nuclear signal components are regulated by a plant protease.