PDBsum entry 4ri0

Hydrolase

PDB id: 4ri0

Contents

Protein chains

306 a.a.

202 a.a.

Ligands

PO4 ×2

Waters ×3

PDB id:

4ri0

Name:

Hydrolase

Title:

Serine protease htra3, mutationally inactivated

Structure:

Serine protease htra3. Chain: a, b, c. Fragment: residues 130-453. Synonym: high-temperature requirement factor a3, pregnancy-related serine protease. Engineered: yes. Mutation: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: htra3, prsp. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

3.27Å R-factor: 0.201 R-free: 0.233

Authors:

J.Osipiuk,P.Glaza,T.Wenta,B.Lipinska,A.Joachimiak,Midwest Center For Structural Genomics (Mcsg)

Key ref:

P.Glaza et al. (2015). Structural and Functional Analysis of Human HtrA3 Protease and Its Subdomains. Plos One, 10, e0131142. PubMed id: 26110759 DOI: 10.1371/journal.pone.0131142

Date:

03-Oct-14 Release date: 29-Oct-14

Protein chain

P83110  (HTRA3_HUMAN) -  Serine protease HTRA3 from Homo sapiens

Seq: 453 a.a.

Struc: 306 a.a.*

Protein chains

P83110  (HTRA3_HUMAN) -  Serine protease HTRA3 from Homo sapiens

Seq: 453 a.a.

Struc: 202 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: Chains A, B, C: E.C.3.4.21.- - ?????

DOI no: 10.1371/journal.pone.0131142

Plos One 10:e0131142 (2015)

PubMed id: 26110759

Structural and Functional Analysis of Human HtrA3 Protease and Its Subdomains.

P.Glaza, J.Osipiuk, T.Wenta, D.Zurawa-Janicka, M.Jarzab, A.Lesner, B.Banecki, J.Skorko-Glonek, A.Joachimiak, B.Lipinska.

ABSTRACT

Human HtrA3 protease, which induces mitochondria-mediated apoptosis, can be a tumor suppressor and a potential therapeutic target in the treatment of cancer. However, there is little information about its structure and biochemical properties. HtrA3 is composed of an N-terminal domain not required for proteolytic activity, a central serine protease domain and a C-terminal PDZ domain. HtrA3S, its short natural isoform, lacks the PDZ domain which is substituted by a stretch of 7 C-terminal amino acid residues, unique for this isoform. This paper presents the crystal structure of the HtrA3 protease domain together with the PDZ domain (ΔN-HtrA3), showing that the protein forms a trimer whose protease domains are similar to those of human HtrA1 and HtrA2. The ΔN-HtrA3 PDZ domains are placed in a position intermediate between that in the flat saucer-like HtrA1 SAXS structure and the compact pyramidal HtrA2 X-ray structure. The PDZ domain interacts closely with the LB loop of the protease domain in a way not found in other human HtrAs. ΔN-HtrA3 with the PDZ removed (ΔN-HtrA3-ΔPDZ) and an N-terminally truncated HtrA3S (ΔN-HtrA3S) were fully active at a wide range of temperatures and their substrate affinity was not impaired. This indicates that the PDZ domain is dispensable for HtrA3 activity. As determined by size exclusion chromatography, ΔN-HtrA3 formed stable trimers while both ΔN-HtrA3-ΔPDZ and ΔN-HtrA3S were monomeric. This suggests that the presence of the PDZ domain, unlike in HtrA1 and HtrA2, influences HtrA3 trimer formation. The unique C-terminal sequence of ΔN-HtrA3S appeared to have little effect on activity and oligomerization. Additionally, we examined the cleavage specificity of ΔN-HtrA3. Results reported in this paper provide new insights into the structure and function of ΔN-HtrA3, which seems to have a unique combination of features among human HtrA proteases.