pZsYellow is a pUC19-derived prokaryotic expression vector, which encodes a variant of wild-type Zoanthus sp. yellow fluorescent protein (ZsYellow) that has been engineered for brighter fluorescence. Wild-type ZsYellow cDNA was originally cloned from a Zoanthus species of coral, native to the Indian and Pacific oceans (1). A single amino acid substitution (Met-128 to Val) has been made to enhance the emission characteristics of ZsYellow (excitation maximum = 531 nm; emission maximum = 540 nm).

The ZsYellow gene was inserted in frame with the lacZ initiation codon from pUC19 so that ZsYellow is expressed from the lac promoter (Plac) in E. coli. The ZsYellow coding sequence is flanked by distinct multiple cloning sites (MCS) at the 5' and 3' ends so that the gene can be easily excised from pZsYellow and subcloned into other expression vectors. An upstream sequence—located just 5' to the ZsYellow gene—has been converted to a Kozak consensus translation initiation site (2) to increase the translation efficiency in eukaryotic expression systems. The pUC backbone of pZsYellow provides a high-copy-number origin of replication (pUC ori) and an ampicillin resistance gene (Ampr) for propagation and selection in E. coli.

載體應(yīng)用

pZsYellow Vector serves as a convenient source of the ZsYellow cDNA. The flanking MCS regions make it possible to excise the ZsYellow coding sequence and insert it into other prokaryotic or eukaryotic expression vectors. Alternatively, the ZsYellow coding sequence can be amplified by PCR.