PDBsum entry 1hm6

Metal, lipid binding protein

PDB id: 1hm6

Contents

Protein chains

343 a.a. *

Ligands

SO4 ×12

Waters ×739

* Residue conservation analysis

PDB id:

1hm6

Name:

Metal, lipid binding protein

Title:

X-ray structure of full-length annexin 1

Structure:

Annexin 1. Chain: a, b. Engineered: yes

Source:

Sus scrofa. Pig. Organism_taxid: 9823. Gene: anx1. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Dimer (from PQS)

Resolution:

1.80Å R-factor: 0.224 R-free: 0.259

Authors:

A.Rosengarth,V.Gerke,H.Luecke

Key ref:

A.Rosengarth et al. (2001). X-ray structure of full-length annexin 1 and implications for membrane aggregation. J Mol Biol, 306, 489-498. PubMed id: 11178908 DOI: 10.1006/jmbi.2000.4423

Date:

04-Dec-00 Release date: 28-Feb-01

Protein chains

P19619  (ANXA1_PIG) -  Annexin A1 from Sus scrofa

Seq: 346 a.a.

Struc: 343 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

DOI no: 10.1006/jmbi.2000.4423

J Mol Biol 306:489-498 (2001)

PubMed id: 11178908

X-ray structure of full-length annexin 1 and implications for membrane aggregation.

A.Rosengarth, V.Gerke, H.Luecke.

ABSTRACT

Annexins comprise a multigene family of Ca2+ and phospholipid- binding proteins. They consist of a conserved C-terminal or core domain that confers Ca2+-dependent phospholipid binding and an N-terminal domain that is variable in sequence and length and responsible for the specific properties of each annexin. Crystal structures of various annexin core domains have revealed a high degree of similarity. From these and other studies it is evident that the core domain harbors the calcium-binding sites that interact with the phospholipid headgroups. However, no structure has been reported of an annexin with a complete N-terminal domain. We have now solved the crystal structure of such a full-length annexin, annexin 1. Annexin 1 is active in membrane aggregation and its refined 1.8 A structure shows an alpha-helical N-terminal domain connected to the core domain by a flexible linker. It is surprising that the two alpha-helices present in the N-terminal domain of 41 residues interact intimately with the core domain, with the amphipathic helix 2-12 of the N-terminal domain replacing helix D of repeat III of the core. In turn, helix D is unwound into a flap now partially covering the N-terminal helix. Implications for membrane aggregation will be discussed and a model of aggregation based on the structure will be presented.

Selected figure(s)

Figure 1.
Figure 1. Ribbon diagrams of one monomer of (a) recombinant porcine annexin 1 comprising protein core and the N-terminal domain and (b) human annexin 1 lacking the first 32 amino acid residues (delta1 to 32 anx I; PDB-code 1AIN). 15 Repeat I is presented in red, repeat II in green, repeat III in blue, repeat IV in purple and the N-terminal domain in yellow. The yellow N-terminal helix in (a) is replacing the two-turn blue helix in (b). Bound calcium ions in delta1-32 annexin 1 are illustrated as yellow spheres. The Figure was prepared using MOLSCRIPT and RASTER3D. 43,44

Figure 3.
Figure 3. Stereo image of the 1.8 Å 3Fo - 2Fc electron density of the N-terminal domain and repeat III, contoured at 1s. The backbone and side-chains are shown in gold. Met3, Val4 and Phe7 are located in a hydrophobic pocket formed by residues Val220, Phe221, Ile224, Leu225 and Phe237 of repeat III. The Figure was prepared using SETOR. 45

The above figures are reprinted by permission from Elsevier: J Mol Biol (2001, 306, 489-498) copyright 2001.

Figures were selected by an automated process.