5B6L

Structure of Deg protease HhoA from Synechocystis sp. PCC 6803

Summary for 5B6L

• Entry DOI: 10.2210/pdb5b6l/pdb
• Descriptor: Putative serine protease HhoA, UNK-UNK-UNK-UNK-TRP, ZINC ION, ... (5 entities in total)
• Functional Keywords: serine protease, hydrolase
• Biological source: Synechocystis sp. PCC 6803 substr. Kazusa; More
• Cellular location: Periplasm : P72780
• Total number of polymer chains: 2
• Total formula weight: 37501.73

Authors

Dong, W.,Wang, J.,Liu, L. (deposition date: 2016-05-30, release date: 2016-09-21, Last modification date: 2024-10-23)

Primary citation

Dong, W.,Wang, J.,Niu, G.,Zhao, S.,Liu, L.
Crystal structure of the zinc-bound HhoA protease from Synechocystis sp. PCC 6803
Febs Lett., 590:3435-3442, 2016

PubMed Abstract: The high temperature requirement A (HtrA) proteases are oligomeric serine proteases essential for protein quality control. HtrA homolog A (HhoA) from the photosynthetic cyanobacterium Synechocystis sp. PCC 6803 assembles into a proteolytically active hexamer. Herein, we present the crystal structure of the hexameric HhoA in complex with the copurified peptide. Our data indicate the presence of three methionines in close proximity to the peptide-binding site of the PDZ domain. Unexpectedly, we observed that a zinc ion is accommodated within the central channel formed by a HhoA trimer. However, neither calcium nor magnesium showed affinity for HhoA. The role of the zinc ion in HhoA was tested in an in vitro proteolytic assay against the nonspecific substrate β-casein and was found to be inhibitory. Our findings provide insights into the regulation of HhoA by a redox-related mechanism involving methionine residues and by zinc ion-binding within the central channel.

PubMed: 27616292
DOI: 10.1002/1873-3468.12416

Experimental method

X-RAY DIFFRACTION (2.801 Å)