Cloning, sequencing and preliminary expression of human RP2 gene

RP 2 is an X linked retinitis pigmentosa gene, which was newly discovered by positional cloning. A polymerase chain reaction (PCR) was conducted to screen a full length cDNA fragment, defined as h RP 2a, which included the coding region of h RP 2, in a human retina cDNA library. h RP 2a gene was cloned into the pJLA503 vector and h RP 2 gene was subcloned into the expression vector pP RO EX HTa. Polymorphism was demonstrated at two sites through DNA sequencing. The recombinant pP RO RP 2 was transformed into Escherichia coli strain DH5α and the expression of a 6×His tagged hRP2 fusion protein was induced by IPTG. Band density scanning of stained gel was performed to estimate the percentage of the recombinant protein in the total bacterial protein. The ratio was 7% when the expression was induced at 30 ℃ and was 5.6 % at 37 ℃. The cloning and expression of h RP 2 gene in E.coli established a basis for the further purification and studies of RP2 for its physiochemical identity, immunohistochemistry and structure function relationship.