Work

Human Exonuclease 1 Functionally Complements Its Yeast Homologues in DNA Recombination, RNA Primer Removal, and Mutation Avoidance

Year: 1999

Type: article

Abstract: Yeast exonuclease 1 (Exo1) is induced during meiosis and plays an important role in DNA homologous recombination and mismatch correction pathways. The human homolog, an 803-amino acid protein, shares 55% similarity to the yeast Exo1. In this report, we show that the enzyme functionally complements Saccharomyces cerevisiae Exo1 in recombination of direct repeat DNA fragments, UV resistance, and mutation avoidance by in vivo assays. Furthermore, the human enzyme suppresses the conditional lethality of a rad27Delta mutant, symptomatic of defective RNA primer removal. The purified recombinant enzyme not only displays 5'-3' double strand DNA exonuclease activity, but also shows an RNase H activity. This result indicates a back-up function of exonuclease 1 to flap endonuclease-1 in RNA primer removal during lagging strand DNA synthesis.

Source: Journal of Biological Chemistry

DOI: 10.1074/jbc.274.25.17893

Authors: Junzhuan Qiu, Ying Qian, Victoria Chen, Min-Xin Guan, Binghui Shen

Institutions: City Of Hope National Medical Center, Beckman Research Institute, California Institute of Technology

Language: English

Topic: DNA Repair Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funder: National Cancer Institute