POMZP3 appears to have resulted from a fusion of DNA sequences derived from 2 distinct loci, specifically through the duplication of two internal exons from the POMZP3 gene and four 3' exons from the ZP3 gene. The 5' end of this gene is similar to the ` coding region of the POMZP3 gene which encodes an integral nuclear pore membrane protein. However, the protein encoded by this gene lacks the nuclear pore localization motif. The 3' end of this gene is similar to the last 4 exons of the zona pellucid glycoprotein 3 (ZP3) gene and the encoded protein retains one zona pellucida domain. Recombinant human POMZP3 protein, fused to His-tag at N-terminus, was expressed in E.coli.