Human exonuclease 1 (EXO1) activity characterization and its function on FLAP structures

TY - JOUR

T1 - Human exonuclease 1 (EXO1) activity characterization and its function on FLAP structures

AU - Keijzers, Guido

AU - Bohr, Vilhelm A

AU - Juel Rasmussen, Lene

PY - 2015/4/25

Y1 - 2015/4/25

N2 - Human exonuclease 1 (EXO1) is involved in multiple DNA metabolism processes, including DNA repair and replication. Most of the fundamental roles of EXO1 have been described in yeast. Here, we report a biochemical characterization of human full-length EXO1. Prior to assay EXO1 on different DNA flap structures, we determined factors essential for the thermodynamic stability of EXO1. We show that enzymatic activity and stability of EXO1 on DNA is modulated by temperature. By characterization of EXO1 flap activity using various DNA flap substrates, we show that EXO1 has a strong capacity for degrading double stranded DNA and has a modest endonuclease or 5' flap activity. Furthermore, we report novel mechanistic insights into the processing of flap structures, showing that EXO1 preferentially cleaves one nucleotide inwards in a double stranded region of a forked and nicked DNA flap substrates, suggesting a possible role of EXO1 in strand displacement.

AB - Human exonuclease 1 (EXO1) is involved in multiple DNA metabolism processes, including DNA repair and replication. Most of the fundamental roles of EXO1 have been described in yeast. Here, we report a biochemical characterization of human full-length EXO1. Prior to assay EXO1 on different DNA flap structures, we determined factors essential for the thermodynamic stability of EXO1. We show that enzymatic activity and stability of EXO1 on DNA is modulated by temperature. By characterization of EXO1 flap activity using various DNA flap substrates, we show that EXO1 has a strong capacity for degrading double stranded DNA and has a modest endonuclease or 5' flap activity. Furthermore, we report novel mechanistic insights into the processing of flap structures, showing that EXO1 preferentially cleaves one nucleotide inwards in a double stranded region of a forked and nicked DNA flap substrates, suggesting a possible role of EXO1 in strand displacement.

U2 - 10.1042/BSR20150058

DO - 10.1042/BSR20150058

M3 - Journal article

C2 - 25913924

SN - 0144-8463

VL - 35

JO - Bioscience Reports

JF - Bioscience Reports

IS - 3

M1 - e00206

ER -