Molecular Cloning of cpcU and Heterodimeric Bilin Lyase Activity Analysis of CpcU and CpcS for Attachment of Phycocyanobilin to Cys-82 on the beta Subunit of Phycocyanin in Arthrospira platensis FACHB314

摘要

A new bilin lyase gene cpcU was cloned from Arthrospira platensis FACHB314 to study the assembly of the phycocyanin -Subunit. Two recombinant plasmids, one contained the phycocyanobilin (PCB) producing genes (hoxI and pcyA), while the other contained the gene of the -Subunit of phycobiliprotein (cpcB) and the lyase gene (cpcU, cpcS, or cpcU/S) were constructed and separately transferred into Escherichia coli in order to test the activities of relevant lyases for catalyzing PCB addition to CpcB during synthesizing fluorescent -PC of A. platensis FACHB314. The fluorescence intensity examination showed that Cys-82 maybe the active site for the -Subunit binding to PCBs and the attachment could be carried out by CpcU, CpcS, or co-expressed cpcU/S in A. platensis FACHB314.