Evidence for a crosslink between c‐heme and a lysine residue in cytochrome P460 of Nitrosomonas europaea

FEBS Letters

Hooper, Alan B.¹  Arciero, David M.¹ 

[1] Department of Genetics and Cell Biology, University of Minnesota, 344 Gortner Labs, 1479 Gortner Ave., St. Paul, MN 55108, USA

关键词: Cytochrome P460;    Nitrosomonas europaea;    Hemeprotein;    Heme modification;    Proteolytic cleavage;   

DOI  :  10.1016/S0014-5793(97)00635-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Sequence analysis of a purified heme-containing tryptic chromopeptide from cytochrome P460 revealed two predominant amino acid residues per cycle. Two peptides present in the chromopeptide with the sequences NLPTAEXAAXHK and DGTVTVXELVSV. Comparison of the data to the gene sequence for the protein revealed that the gaps in the first peptide (indicated by X's) code for C residues, confirming the prediction of a c-heme binding motif. The gap in the sequence in the second peptide at cycle 7 is predicted by the gene sequence to be a K. The results suggest that the lysine residue is crosslinked in some manner to the porphyrin macrocycle, possibly mimicking the tyrosine crosslink found for the heme P460 of HAO. While a common role for the crosslinked residues in HAO and cytochrome P460 is difficult to ascertain due to the dissimilarities in side chain structure, it may be related to the similar pK _a values for lysine and tyrosine.

【 授权许可】

Unknown