TY - JOUR

T1 - Arabidopsis thaliana peroxidase N

T2 - structure of a novel neutral peroxidase

AU - Mirza, Osman Asghar

AU - Henriksen, A

AU - Ostergaard, L

AU - Welinder, K G

AU - Gajhede, M

PY - 2000/3

Y1 - 2000/3

N2 - The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C (HRP C). HRP C is 54% identical to ATP N in sequence. When the structures of four class III plant peroxidases are superimposed, the regions with structural differences are non-randomly distributed; all are located in one half of the molecule. The architecture of the haem pocket of ATP N is very similar to that of HRP C, in agreement with the low small-molecule substrate specificity of all class III peroxidases. The structure of ATP N suggests that the pH dependence of the substrate turnover will differ from that of HRP C owing to differences in polarity of the residues in the substrate-access channel. Since there are fewer hydrogen bonds to haem C17 propionate O atoms in ATP N than in HRP C, it is suggested that ATP N will lose haem more easily than HRP C. Unlike almost all other class III plant peroxidases, ATP N has a free cysteine residue at a similar position to the suggested secondary substrate-binding site in lignin peroxidase.

AB - The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C (HRP C). HRP C is 54% identical to ATP N in sequence. When the structures of four class III plant peroxidases are superimposed, the regions with structural differences are non-randomly distributed; all are located in one half of the molecule. The architecture of the haem pocket of ATP N is very similar to that of HRP C, in agreement with the low small-molecule substrate specificity of all class III peroxidases. The structure of ATP N suggests that the pH dependence of the substrate turnover will differ from that of HRP C owing to differences in polarity of the residues in the substrate-access channel. Since there are fewer hydrogen bonds to haem C17 propionate O atoms in ATP N than in HRP C, it is suggested that ATP N will lose haem more easily than HRP C. Unlike almost all other class III plant peroxidases, ATP N has a free cysteine residue at a similar position to the suggested secondary substrate-binding site in lignin peroxidase.

KW - Amino Acid Sequence

KW - Arabidopsis

KW - Crystallization

KW - Crystallography, X-Ray

KW - Escherichia coli

KW - Models, Molecular

KW - Molecular Sequence Data

KW - Peroxidases

KW - Plant Proteins

KW - Protein Conformation

KW - Recombinant Fusion Proteins

KW - Sequence Alignment

KW - Sequence Homology, Amino Acid

M3 - Journal article

C2 - 10713531

VL - 56

SP - 372

EP - 375

JO - Acta Crystallographica Section D: Structural Biology

JF - Acta Crystallographica Section D: Structural Biology

SN - 2059-7983

IS - Pt 3

ER -