Based on homology analysis of armino acid sequences,SYNW2013 and SYNW2012 from Synechococcus sp. WH8102 were found, which were similar to CpeY and CpeZ from Fremyella diplosiphon. The respective genes are named as cpeY-Syn and cpeZ-Syn, and were then constructed into different expression vectors via molecular cloning techniques. Using a heterologous coexpression system in Escherichia coli, CpeY-Syn and CpeZ-Syn could cooperatively catalyze the covalent attachment of phycoerythrobilin to CpeA. The experiments also showed that CpeY-Syn alone could ligate phycoerythrobilin to CpeA,but the yield of PEB-CpeA was lower than that in the presence of both CpeY-Syn and CpeZ-Syn. No fluorescent products were observed in the absence of CpeY-Syn. Similar to the CpcE/F lyases,which are responsible for the covalent attachment of phycocyanobilin to CpcA,the CpeY/Z-Syn lyases exclusively catalyzed the covalent attachment of phycoerythrobilin to CpeA. They belong to the E/F type of lyases of phycobiliproteins.%通过蛋白质序列相似性分析,在Synechococcus sp.strain WH8102里面找到了与Fremyella diplosiphon的藻红蛋白裂合酶编码基因cpey、cpeZ同源的基因SYNW2013、SYNW2012,分别命名为cpeY-Syn、cpeZ-Syn.通过分子克隆技术,将其构建在不同的表达载体上.通过大肠杆菌体内表达系统,藻红胆素(PEB)在CpeY-Syn和CpeZ-Syn的共同催化下,共价连接到藻红蛋白o亚基脱辅助基蛋白CpeA上,生成色素蛋白PEB-CpeA.实验也表明,在缺少CpeY-Syn的情况下,不能产生色素蛋白,而在缺少CpeZ-Syn的情况下,色素蛋白产率有所降低.与CpcE/F催化藻蓝蛋白α亚基共价连接藻蓝胆素(PCB)一样,CpeY/Z-Syn专一性的催化藻红蛋白α亚基与PEB的连接,它们属于同一类的蛋白家族.
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