The complete amino acid sequence of chitinase-a from the seeds of rye (Secale cereal).
The complete amino acid sequence of rye seed chitinase-a (RSC-a) has been analyzed. RSC-a was cleaved with cyanogen bromide and the resulting three fragments, CB1, CB2, and CB3, were separated by gel filtration. The amino acids of the N-terminal fragment CB1 were sequenced by analyzing the peptides produced by digestion with trypsin, lysylendopeptidase, or pepsin of reduced S-carboxymethylated or S-aminoethylated CB1. The sequences of fragments CB2 and CB3 were established by sequencing the tryptic peptides from reduced S-carboxymethylated CB2 and CB3, and by aligning them with the sequence of rye seed chitinase-c (RSC-c) to maximize sequence homology. The complete amino acid sequence of RSC-a was established by connecting these three fragments. RSC-a consists of 302 amino acid residues including hydroxyproline residues, and has a molecular mass of 31,722 Da. RSC-a is basic protein with a cysteine-rich amino terminal domain, indicating that this enzyme belongs to class I chitinases. The amino acid sequence of RSC-a showed that the sequence from Gly60 to C-terminal Ala302 in this enzyme corresponds to that of RSC-c belonging to class II chitinases with 92% identity, and that RSC-a has high similarity to other plant class I chitinases but a longer hinge region and an extra disulfide bond.
Yamagami
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Laboratory of Protein Chemistry & Engineering, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Funatsu
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D000595:Amino Acid Sequence; D002688:Chitinases / Q000737:chemistry* / Q000302:isolation & purification; D003488:Cyanogen Bromide; D007527:Isoenzymes / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D012434:Secale / Q000201:enzymology*; D012639:Seeds / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid
D007527:Isoenzymes; D010455:Peptides; D010940:Plant Proteins; D002688:Chitinases; D003488:Cyanogen Bromide