Abstract
Cystatins, cysteine protease inhibitors, are widely distributed among eukaryotes. We reevaluated the structure of the gene cpiC, a gene encoding the third identified member of cystatin family (cystatin A3) that was predicted in the genome database of the social amoeba Dictyostelium discoidium (dictyBase) but remained controversial. We determined the sequences of cDNA and PCR-amplified genomic DNA fragment and found a critical error in the registered nucleotide sequence. The corrected cystatin A3 gene has an open reading frame (ORF) without intron sequence interruption and encodes 94 amino acids (aa), in contrast to the previously predicted sequence of either 80, 82 or 118 aa. The cDNA has an unusual internal poly(A) sequence of 31 adenines, which immediately follows the translation termination codon (TAA) located 146 nucleotides upstream of the post-transcriptional polyadenylation site. The amino acid sequence of Dictyostelium cystatin A3 shows a high similarity to those of previously reported Dictyostelium cystatins as well as Family I cystatins of higher eukaryotes.
Original language | English (US) |
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Pages (from-to) | 257-264 |
Number of pages | 8 |
Journal | Molecular Biology Reports |
Volume | 32 |
Issue number | 4 |
DOIs | |
State | Published - Dec 2005 |
Externally published | Yes |
Keywords
- Cystatin
- Cysteine protease inhibitor
- Intron
- Open reading frame
- dictyBase
- poly(A)
ASJC Scopus subject areas
- Molecular Biology
- Genetics