caa a22 4500 397555458 CHVBK 20180308164800.0 cr unu---uuuuu 161202e199612 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021525 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021525 N-Terminal Processing and Amino Acid Sequence of Two Isoforms of Nitric Oxide Reductase Cytochrome P450nor from Fusarium oxysporum [Elektronische Daten] [Kazuhiko Nakahara, Hirofuni Shoun] Cytochrome P450nor (P450nor), a nitric oxide reductase involved in the denitrifying system of the fungus Fusarium oxysporum revealed molecular multiplicity. Two isoforms of P450nor, termed P450norA (norA) and P450norB (norB), were isolated. They had distinct isoelectric points of 5.1 (norA) and 4.9 (norB). However, their catalytic, spectroscopic, and immunological properties were almost identical. Partial amino acid sequences, involving 263 amino acid residues of norA and 278 residues of norB among 404 and 402 residues, respectively, were determined. Corresponding sequences in the isoforms were identical, and all of the determined partial sequences of norA or norB coincided with the sequence deduced from the CYP 55 gene or its cDNA. The amino acid sequence determination ruled out the possibility that there is a redox center in P450nor derived from amino acid residues, e.g., quinonoid cofactors. The only difference between norA and norB was in their N-termini. The N-terminus of norA was a threonine residue, whereas that of norB was an N-acetylated alanyl residue and norB was shorter by 2 residues than norA. The results suggested that norA and norB may be the products of the same gene, but translated from different initiation codons. The hypothetical precursor of norA would have a presequence containing targeting and sorting signals for transportation to the intermembrane space of mitochondria. This is consistent with the results of a Western-blot analysis which showed that norA was recovered only in particulate fractions, whereas norB was in the soluble fraction. It is therefore likely that the intracellular localizations as well as the N-termini of norA and norB are different, owing to the differences in the translational initiation codons and co/post-translational processings. © 1996 BY THE JOURNAL OF BIOCHEMISTRY Regular Papers nationallicence amino acid sequence nationallicence amino-terminal processing nationallicence cytochrome P450nor nationallicence Fusarium oxysporum nationallicence P450nor isoforms nationallicence Nakahara Kazuhiko Institute of Applied Biochemistry, University of Tsukuba, Tsukuba, Ibaraki 305 aut Shoun Hirofuni Institute of Applied Biochemistry, University of Tsukuba, Tsukuba, Ibaraki 305 aut The Journal of Biochemistry Oxford University Press 120/6(1996-12), 1082-1087 0021-924X 120:6<1082 1996 120 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021525 text/html Onlinezugriff via DOI 1 other jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021525 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nakahara Kazuhiko Institute of Applied Biochemistry, University of Tsukuba, Tsukuba, Ibaraki 305 aut NATIONALLICENCE 700 1- Shoun Hirofuni Institute of Applied Biochemistry, University of Tsukuba, Tsukuba, Ibaraki 305 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 120/6(1996-12), 1082-1087 0021-924X 120:6<1082 1996 120 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford