1atj
From Proteopedia
RECOMBINANT HORSERADISH PEROXIDASE C1A
Overview
The crystal structure of horseradish peroxidase isozyme C (HRPC) has been solved to 2.15 A resolution. An important feature unique to the class III peroxidases is a long insertion, 34 residues in HRPC, between helices F and G. This region, which defines part of the substrate access channel, is not present in the core conserved fold typical of peroxidases from classes I and II. Comparison of HRPC and peanut peroxidase (PNP), the only other class III (higher plant) peroxidase for which an X-ray structure has been completed, reveals that the structure in this region is highly variable even within class III. For peroxidases of the HRPC type, characterized by a larger FG insertion (seven residues relative to PNP) and a shorter F' helix, we have identified the key residue involved in direct interactions with aromatic donor molecules. HRPC is unique in having a ring of three peripheral Phe residues, 142, 68 and 179. These guard the entrance to the exposed haem edge. We predict that this aromatic region is important for the ability of HRPC to bind aromatic substrates.
About this Structure
1ATJ is a Single protein structure of sequence from Armoracia rusticana. Full crystallographic information is available from OCA.
Reference
Crystal structure of horseradish peroxidase C at 2.15 A resolution., Gajhede M, Schuller DJ, Henriksen A, Smith AT, Poulos TL, Nat Struct Biol. 1997 Dec;4(12):1032-8. PMID:9406554 Page seeded by OCA on Fri May 2 10:40:26 2008
