cDNA and genomic structures of arrowhead proteinase inhibitors.
Arrowhead double-headed proteinase inhibitors A and B consist of 150 amino acid residues with three disulfide bonds. Based on their primary structures, three cDNA fragments of the inhibitors were amplified in vitro by the PCR method using a constructed arrowhead cDNA library as a template. With the overlapping sequences, the full-length cDNA sequences of the inhibitors were then ascertained. The open reading frame encodes a pre-inhibitor, including a 24 residue signal peptide. The deduced amino acid sequences are consistent in principle with those determined by primary structure analysis, except that there are seven extra residues in the C-terminal part of the inhibitors, which might be cleaved off by proteinase post-processing immediately after protein synthesis. It is worth pointing out that cDNAs of both inhibitors A and B contain an 87 bp intron in the AAG codon of residue Lys-97. According to the elucidated cDNA sequences, the structural genes of inhibitors A and B were amplified using the total cDNA or genomic DNA of arrowhead as a PCR template. It was indicated that both the cDNA and genomic structures of inhibitors A and B have the same sequences.
Xu
W F
WF
Shanghai Institute of Biochemistry, Academia Sinica, China.
Tao
W K
WK
Gong
Z Z
ZZ
Chi
C W
CW
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA; D015723:Gene Library; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011480:Protease Inhibitors
C080655:API-A protein, Sagittaria sagittifolia; D010940:Plant Proteins; D011480:Protease Inhibitors; C047493:proteinase inhibitor B, arrowhead root; D004247:DNA