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BRCT domain of DNA polymerase μ has DNA ‐binding activity and promotes the DNA polymerization activity
Author(s) -
Matsumoto Takuro,
Go Kaori,
Hyodo Mariko,
Koiwai Kotaro,
Maezawa So,
Hayano Takahide,
Suzuki Masahiro,
Koiwai Osamu
Publication year - 2012
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2012.01628.x
Subject(s) - dna polymerase , biology , dna clamp , dna polymerase ii , dna polymerase mu , microbiology and biotechnology , dna , polymerase , dna polymerase i , hmg box , dna polymerase delta , processivity , biochemistry , dna binding protein , circular bacterial chromosome , gene , rna , reverse transcriptase , transcription factor
DNA polymerase μ (pol μ) catalyzes nonhomologous end‐joining in DNA double‐stranded break repair. Pol μ consists of an amino‐terminal BRCA 1 carboxyl‐terminal homology ( BRCT ) domain and a pol β‐like region, which contains the catalytic site. By DNA cellulose column chromatography, using full‐length pol μ and five different deletion mutants, we found that the amino‐terminal region has double‐stranded DNA (ds DNA )‐binding activity. Pol μ without BRCT domain reduces the DNA polymerization activity when compared to full‐length pol μ. Observation by atomic force microscopy showed that full‐length pol μ binds to the ends and middle part of ds DNA . Pol μ lacking the amino‐terminal region or with a mutation within the BRCT domain bound only to DNA ends, whereas the amino‐terminal region with the BRCT domain bound to both the ends and the middle part of ds DNA (mpd DNA ). Terminal deoxynucleotidyltransferase, which, like pol μ, belongs to the X family DNA polymerases, also bound to mpd DNA through its amino‐terminal region.