PDBsum entry 1aii

Calcium/phospholipid binding protein

PDB id: 1aii

Contents

Protein chain

322 a.a. *

Ligands

SO4

ETA

Metals

_CA ×5

Waters ×233

* Residue conservation analysis

PDB id:

1aii

Name:

Calcium/phospholipid binding protein

Title:

Annexin iii

Structure:

Annexin iii. Chain: a. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 562. Other_details: plasmid source puc (biogen, cambridge, ma, usa)

Resolution:

1.95Å R-factor: 0.196 R-free: 0.237

Authors:

A.Lewit-Bentley,B.Perron

Key ref:

B.Perron et al. (1997). Can enzymatic activity, or otherwise, be inferred from structural studies of annexin III? J Biol Chem, 272, 11321-11326. PubMed id: 9111038 DOI: 10.1074/jbc.272.17.11321

Date:

28-Nov-96 Release date: 12-Mar-97

Protein chain

P12429  (ANXA3_HUMAN) -  Annexin A3 from Homo sapiens

Seq: 323 a.a.

Struc: 322 a.a.

DOI no: 10.1074/jbc.272.17.11321

J Biol Chem 272:11321-11326 (1997)

PubMed id: 9111038

Can enzymatic activity, or otherwise, be inferred from structural studies of annexin III?

B.Perron, A.Lewit-Bentley, B.Geny, F.Russo-Marie.

ABSTRACT

Annexin III, a putative inositol (1,2)-phosphohydrolase, was co-crystallized with inositol 2-phosphate, the inhibitor of the reaction, and its structure was solved to 1.95 A resolution. No enzyme active site was observed in the structure. Assays for enzymatic activity were also negative. Search for annexin III-inositol phosphate interactions using the BIAcoreTM system revealed an affinity for inositol cyclic (1,2)-phosphate, suggesting annexin III may sequester the molecule in the cell. The BIAcoreTM system used with different phospholipids showed that annexin III displays specificity for phosphatidylethanolamine, but not for phosphatidylinositols. Interestingly, a molecule of ethanolamine was found bound to the protein in the crystal structure. Coupled with the fact that this is a particularly abundant phospholipid in granules specific to neutrophils, cells where annexin III is highly expressed, our finding could be pointing to a physiological role of annexin III.

Selected figure(s)

Figure 4.
Fig. 4. Superposition of the C backbone of native annexin III (black) on annexin III with inositol 2-phosphate in the crystallization medium (gray), viewed down the local 2-fold axis (figure prepared^ using the MOLSCRIPT program (33)).

Figure 5.
Fig. 5. A model of the interaction of the third domain in annexin III with phospholipids. The position of the ethanolamine^ group is given by our results, that of the phosphate of the phosphatidyl^ serine from analogy with the sulfate ion interacting with the^ principal calcium site in annexin V (26). The phosphatidylserine^ coordinates were kindly supplied by A. Sanson (34). Calcium^ ions are red, phosphatidylserine is dark blue, phosphatidylethanolamine^ is green, and the Trp-191 side chain is cyan.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (1997, 272, 11321-11326) copyright 1997.

Figures were selected by an automated process.