PDBsum entry 1vfi

Metal binding protein

PDB id: 1vfi

Contents

Protein chain

95 a.a.

PDB id:

1vfi

Name:

Metal binding protein

Title:

Solution structure of vanabin2 (ruh-017), a vanadium-binding protein from ascidia sydneiensis samea

Structure:

Vanadium-binding protein 2. Chain: a. Fragment: residues 1-95. Synonym: vanabin2, ruh-017. Engineered: yes

Source:

Ascidia sydneiensis samea. Organism_taxid: 79730. Strain: samea. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

NMR struc:

20 models

Authors:

T.Hamada,H.Hirota,M.Asanuma,F.Hayashi,N.Kobayashi,T.Ueki,H.Michibata, S.Yokoyama,Riken Structural Genomics/proteomics Initiative (Rsgi)

Key ref:

T.Hamada et al. (2005). Solution structure of Vanabin2, a vanadium(IV)-binding protein from the vanadium-rich ascidian Ascidia sydneiensis samea. J Am Chem Soc, 127, 4216-4222. PubMed id: 15783203 DOI: 10.1021/ja042687j

Date:

13-Apr-04 Release date: 22-Mar-05

Protein chain

Q86BW2  (VBP2_ASCSS) -  Vanadium-binding protein 2 from Ascidia sydneiensis samea

Seq: 120 a.a.

Struc: 95 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.1.13.-.-

DOI no: 10.1021/ja042687j

J Am Chem Soc 127:4216-4222 (2005)

PubMed id: 15783203

Solution structure of Vanabin2, a vanadium(IV)-binding protein from the vanadium-rich ascidian Ascidia sydneiensis samea.

T.Hamada, M.Asanuma, T.Ueki, F.Hayashi, N.Kobayashi, S.Yokoyama, H.Michibata, H.Hirota.

ABSTRACT

Ascidians belonging to the suborder Phlebobranchia are known to accumulate high levels of a transition metal, vanadium, in their blood cells, called vanadocytes, although the mechanism for this biological phenomenon remains unclear. Recently, we identified vanadium(IV)-binding proteins, designated as Vanabins, from vanadium-accumulating ascidians. Here, we report the first 3D structure of Vanabin2 from an ascidian, Ascidia sydneiensis samea, in an aqueous solution. The structure revealed a novel bow-shaped conformation, with four alpha-helices connected by nine disulfide bonds. There are no structural homologues reported so far. The 15N heteronuclear single-quantum coherence (HSQC) perturbation experiments of Vanabin2 indicated that vanadyl cations, which are exclusively localized on the same face of the molecule, are coordinated by amine nitrogens derived from amino acid residues such as lysines, arginines, and histidines, as suggested by the electron paramagnetic resonance (EPR) results. The present NMR studies provide information that will contribute toward elucidating the mechanism of vanadium accumulation in ascidians.