The cDNA sequence of a neutral horseradish peroxidase.
A cDNA clone encoding a horseradish (Armoracia rusticana) peroxidase has been isolated and characterized. The cDNA contains 1378 nucleotides excluding the poly(A) tail and the deduced protein contains 327 amino acids which includes a 28 amino acid leader sequence. The predicted amino acid sequence is nine amino acids shorter than the major isoenzyme belonging to the horseradish peroxidase C group (HRP-C) and the sequence shows 53.7% identity with this isoenzyme. The described clone encodes nine cysteines of which eight correspond well with the cysteines found in HRP-C. Five potential N-glycosylation sites with the general sequence Asn-X-Thr/Ser are present in the deduced sequence. Compared to the earlier described HRP-C this is three glycosylation sites less. The shorter sequence and fewer N-glycosylation sites give the native isoenzyme a molecular weight of several thousands less than the horseradish peroxidase C isoenzymes. Comparison with the net charge value of HRP-C indicates that the described cDNA clone encodes a peroxidase which has either the same or a slightly less basic pI value, depending on whether the encoded protein is N-terminally blocked or not. This excludes the possibility that HRP-n could belong to either the HRP-A, -D or -E groups. The low sequence identity (53.7%) with HRP-C indicates that the described clone does not belong to the HRP-C isoenzyme group and comparison of the total amino acid composition with the HRP-B group does not place the described clone within this isoenzyme group. Our conclusion is that the described cDNA clone encodes a neutral horseradish peroxidase which belongs to a new, not earlier described, horseradish peroxidase group.
Bartonek-Roxå
E
E
Department of Biotechnology, Lund University, Sweden.
Eriksson
H
H
Mattiasson
B
B
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D015723:Gene Library; D006735:Horseradish Peroxidase / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid
D007527:Isoenzymes; D004247:DNA; D006735:Horseradish Peroxidase