Structure and chromosome location of human OGG1.

OGG1 (alias MMH) encodes an 8-hydroxyguanine glycosylase, functionally homologous to bacterial mutM. Here, we report its genomic structure and fine chromosome location. The human OGG1 gene corresponding to the isoform 1 transcripts, consists of seven exons, spanning 7,421 bps, while an alternative additional exon, utilized for isoform 2, is located approximately 9 kb downstream. TATA-like sequence was not found in the 5'-upstream region, common in so-called "housekeeping" genes. The last 55 bases of the 3' untranslated region in exon 7 were unexpectedly conserved among species, presumably because the 3' end of the CAMK1 gene, which is transcribed convergently on the opposite strand, is overlapped at the 3' end. By radiation hybrid panel mapping, OGG1 was localized between WI-4179 and AFMA216ZG1 at 3p26, proximal to the VHL gene.