Repeat arrays in cellular DNA related to the Epstein-Barr virus IR3 repeat.

We isolated clones and determined the sequence of portions of mouse and human cellular DNA which cross-hybridize strongly with the IR3 repetitive region of Epstein-Barr virus. The sequences were found to be tandem arrays of a simple sequence based on the triplet GGA, very similar to the IR3 repeat. The cellular repeats have distinct differences from the viral repeat region, however, and their sequences do not appear capable of being translated into a purely glycine-plus-alanine protein domain like the portion of the Epstein-Barr nuclear antigen coded by IR3. Although the relationship between IR3 and the cellular repeats is left unclear, the cellular repeats have many interesting features. The tandem arrays are about 1 to several kilobases long, much shorter than satellite tandem repeats and larger than other interspersed, tandem repeats. Each of the repeats is a distinct variation, perhaps diverged from a common sequence, (GGA)n. This family is present in the genomes of all species tested and appears to be a ubiquitous feature of all higher eucaryotic genomes.