4WRI

Crystal structure of okadaic acid binding protein 2.1

Summary for 4WRI

• Entry DOI: 10.2210/pdb4wri/pdb
• Descriptor: Okadaic acid binding protein 2-alpha, OKADAIC ACID (3 entities in total)
• Functional Keywords: inhibitor, toxin, toxin-toxin inhibitor complex, toxin/toxin inhibitor
• Biological source: Halichondria okadai (Marine sponge)
• Total number of polymer chains: 1
• Total formula weight: 23624.01

Authors

Ehara, H.,Makino, M.,Kodama, K.,Ito, T.,Sekine, S.,Fukuzawa, S.,Yokoyama, S.,Tachibana, K. (deposition date: 2014-10-24, release date: 2015-05-27, Last modification date: 2020-02-05)

Primary citation

Ehara, H.,Makino, M.,Kodama, K.,Konoki, K.,Ito, T.,Sekine, S.,Fukuzawa, S.,Yokoyama, S.,Tachibana, K.
Crystal Structure of Okadaic Acid Binding Protein 2.1: A Sponge Protein Implicated in Cytotoxin Accumulation
Chembiochem, 16:1435-1439, 2015

PubMed Abstract: Okadaic acid (OA) is a marine polyether cytotoxin that was first isolated from the marine sponge Halichondria okadai. OA is a potent inhibitor of protein serine/threonine phosphatases (PP) 1 and 2A, and the structural basis of phosphatase inhibition has been well investigated. However, the role and mechanism of OA retention in the marine sponge have remained elusive. We have solved the crystal structure of okadaic acid binding protein 2.1 (OABP2.1) isolated from H. okadai; it has strong affinity for OA and limited sequence homology to other proteins. The structure revealed that OABP2.1 consists of two α-helical domains, with the OA molecule deeply buried inside the protein. In addition, the global fold of OABP2.1 was unexpectedly similar to that of aequorin, a jellyfish photoprotein. The presence of structural homologues suggested that, by using similar protein scaffolds, marine invertebrates have developed diverse survival systems adapted to their living environments.

PubMed: 25965326
DOI: 10.1002/cbic.201500141

Experimental method

X-RAY DIFFRACTION (1.4 Å)