Human ubiquitin genes: One member of the UbB gene subfamily is a tetrameric non‐processed pseudogene

Abstract
The human ubiquitin gene family consists of three subfamilies. One of these, the UbB subfamily, includes a functional gene coding for a polyubiquitin protein that contains three ubiquitin copies tandemly repeated, as well as three pseudogenes of the processed type. We have now isolated a fifth human UbB type gene, different from any of the previously identified ones. This newly isolated gene is a tetrameric pseudogene which has presumably arisen by unequal crossing‐over of two ancestral trimeric alleles. Southern blotting data indicate that all members of the human UbB gene subfamily are now accounted for.