PDBsum entry 1vnc

Oxidoreductase

PDB id: 1vnc

Contents

Protein chain

576 a.a.

Ligands

VO4-AZI

Waters ×429

References listed in PDB file

Key reference

• Title: X-Ray structure of a vanadium-Containing enzyme: chloroperoxidase from the fungus curvularia inaequalis.
• Authors: A.Messerschmidt, R.Wever.
• Ref.: Proc Natl Acad Sci U S A, 1996, 93, 392-396.
• PubMed id: 8552646

Note In the PDB file this reference is annotated as "TO BE PUBLISHED". The citation details given above were identified by an automated search of PubMed on title and author names, giving a percentage match of 94%.

Abstract

The chloroperoxidase (EC 1.11.1.-) from the fungus Curvularia inaequalis belongs to a class of vanadium enzymes that oxidize halides in the presence of hydrogen peroxide to the corresponding hypohalous acids. The 2.1 A crystal structure (R = 20%) of an azide chloroperoxidase complex reveals the geometry of the catalytic vanadium center. Azide coordinates directly to the metal center, resulting in a structure with azide, three nonprotein oxygens, and a histidine as ligands. In the native state vanadium will be bound as hydrogen vanadate(V) in a trigonal bipyramidal coordination with the metal coordinated to three oxygens in the equatorial plane, to the OH group at one apical position, and to the epsilon 2 nitrogen of a histidine at the other apical position. The protein fold is mainly alpha-helical with two four-helix bundles as main structural motifs and an overall structure different from other structures. The helices pack together to a compact molecule, which explains the high stability of the protein. An amino acid sequence comparison with vanadium-containing bromoperoxidase from the seaweed Ascophyllum nodosum shows high similarities in the regions of the metal binding site, with all hydrogen vanadate(V) interacting residues conserved except for lysine-353, which is an asparagine.