Analysis on promoter elements of cpc operon from Arthrospira platensis

On the basis of bioinformatics analysis, six putative promoters were isolated from the upstream sequence of c-phycocyanin gene of Arthrospira platensis FACHB341 through site-directed mutagenesis, and the transcriptional pattern of c-phycocyanin gene was determined by SmartRace. Results showed that each isolated promoter drived the expression of gfp in E.coli, and Promoter Ⅲ was the strongest one according to the GFP level. Only one transcript of c-phycocyanin gene was found under experimental conditions, and the transcription start site G was located at the -285 bp upstream of the start codon, from which it could be inferred that the transcript was from the promotion of Promoter Ⅰ.