Aspartic proteinase genes in the Brassicaceae Arabidopsis thaliana and Brassica napus.

摘要

Active aspartic proteinase was isolated from B. napus seeds and the peptide sequence used to generate primers for PCR. cDNA and genomic clones for aspartic proteinases were isolated from the closely related Brassicaceae species A. thaliana and B. napus. The Arabidopsis cDNA represents a single gene, while Brassica has at least 4 genes. Like other plant aspartic proteinases, the two Brassicaceae enzymes contain an extra protein domain of about 100 amino acids relative to the mammalian forms. The intron/exon arrangement in the Brassica genomic clone is significantly different from that in mammalian genes. As the proteinase is isolated from seeds, the same tissue where 2S albumins are processed, this implies expression of one of the aspartic proteinase genes there. Nucleotide sequence data have been submitted to the EMBL/GenBank/DDBJ databases under the accession numbers U51306, U55033 and U55032 for pSG2J2 (A. thaliana cDNA), pKD421 (partial B. napus genomic PCR fragment) and pKD425 (B. napus genomic clone), respectively.