Full text loading...
Abstract
The gene (nspC) encoding carboxynorspermidine decarboxylase (CANS DC), the last enzyme in norspermidine biosynthesis, in Vibrio alginolyticuswas isolated by immuno-screening and its complete nucleotide sequence was determined. Sequence analysis of the subcloned fragment (2.0 kb) revealed an ORF of 1131 bp encoding a protein of 377 amino acids with a calculated molecular mass of 42008 Da. The sequence of 20 N-terminal amino acids of purified CANS DC was found to be identical to that predicted from the nspCgene. A putative ribosome binding sequence was observed 8 bp upstream from the translation start site (ATG), and promoter- and terminator-like sequences were detected upstream and downstream of the ORF, respectively. Database searches identified no similar proteins, but the deduced amino acid sequence contained a putative pyridoxal 5′-phosphate binding region similar to those of the bacterial meso-2,6-diaminopimelate decarboxylases and eukaryotic ornithine decarboxylases. Another full ORF was found on the opposite strand downstream from the nspCgene. It encoded a protein of 69 amino acids with a calculated molecular mass of 7441 Da, which exhibited some weak similarity to ScrR,a repressor protein of V. alginolyticus, in the helix-turn-helix DNA binding domain, but did not appear to be expressed in the host cells.
- Published Online: