ISSN:
1617-4623
Keywords:
Dictyostelium
;
Cysteine proteinase
;
Gene sequencing
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary A developmentally regulated DNA sequence was isolated from a Dictyostelium discoideum genomic library by cross hybridization with a cDNA clone of cysteine proteinase I. The genomic fragment represents a different but related gene, designated cysteine proteinase II. This sequence is unique in the genome and it hybridizes to a polyA+ RNA of 1.5 kb length, which is produced after the aggregation period. From the determination of polarity of transcription and from the nucleotide sequence, it was shown that the isolated fragment representing about a third of the gene includes its 3′ end. The open reading frame ends with a termination codon TAA and is not interrupted by intervening sequences. The flanking untranslated sequence beyond the 3′ terminus is very A+T rich (91%) and includes a sequence, ATTAAA, known to be important in polyA addition. A striking homology in the corresponding amino acid sequence was found not only with cysteine proteinase I of Dictyostelium discoideum but also with other known cysteine proteases from plants and from mammals. The strongest homology is observed especially around the cysteine at the active site identified in some of these enzymes. Interestingly the organization of cysteine proteinase I and II of Dictyostelium discoideum differs considerably. The C terminal region of the latter corresponds to the N terminal one of the former.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00333975
