Molecular cloning, expression and chromosomal localisation of the mouse Rev3l gene, encoding the catalytic subunit of polymerase zeta

The REV3 gene of Saccharomyces cerevisiae encodes the catalytic subunit of DNA polymerase zeta which is involved in translesion synthesis. The mouse homolog of this gene, Rev3l, was cloned and sequenced. The gene encodes a putative protein of 3122 amino acids. The sequence conservation to its yeast counterpart is restricted to several regions. In the carboxy-terminal part of the protein all six domains are present that are characteristic for alpha-type DNA polymerases. In the amino-terminal part of the protein two regions can be identified with considerable similarity to the NT boxes of mouse polymerase delta. In addition, a region of 60 residues unique for the REV3 homologs can be found in the middle part of the protein. The mouse REV3L protein shows strong sequence conservation with the recently cloned human REV3L protein (86% identity overall). Northern blot analysis of various tissues of the mouse revealed that transcription of the Rev3l gene was highest in brain, ovaries and testis. The human REV3L gene was localised to the long arm of chromosome 6, region 21-22. The mouse equivalent maps to chromosome 10, distal to the c-myb gene, close to the Macs gene.