K. Baier et al., EVIDENCE FOR PROPEPTIDE-ASSISTED FOLDING OF THE CALCIUM-DEPENDENT PROTEASE OF THE CYANOBACTERIUM ANABAENA, European journal of biochemistry, 241(3), 1996, pp. 750-755
The Ca2+-dependent protease of the cyanobacterium Anabaena variabilis
is a cytoplasmic enzyme with a substrate specificity like trypsin. Its
previously published DNA sequence [Maldener, I., Lockau, W., Cai, Y.
& Wolk, C. P. (1991) Mol. Gen. Genet. 225, 113-120] contained a sequen
cing error. Here report the corrected sequence which shows, that the C
a2+-protease belongs to the family of subtilases (subtilisin-like seri
ne proteases). Consistent with its cytoplasmic localization. a pre-seq
uence is not found. The enzyme is produced as a precursor with a large
amino-terminal propeptide. Expression of the pro-region and mature re
gion (protease domain) in Escherichia coli cells in trans demonstrates
that formation of the active enzyme requires the propeptide. The resu
lts demonstrate that propeptide-assisted protein folding also occurs w
ith cytoplasmic enzymes, in support of the hypothesis that this mechan
ism is a widespread phenomenon.