Characterization of the properties of a human homologue of Escherichia coli RecQ from xeroderma pigmentosum group C and from HeLa cells.
We showed that DNA-dependent ATPase Q1 (DNA helicase Q1) from xeroderma pigmentosum complementation group C (XP-C) cells elutes from FPLC Mono Q column at higher concentrations of KCl than that from other human cells (35). We purified DNA helicase Q1 from XP-C and HeLa cells. The purified fractions of both cells contained a major polypeptide with a molecular mass of 73 kDa and had the same enzymatic properties, including salt- and temperature-sensitivity. Characterization using an anti-DNA helicase Q1 antibody indicated that this enzyme localized in the nuclei and was not modified by incorporating phosphate groups through phosphorylation and ADP-ribosylation. No interactions of DNA helicase Q1 with other proteins were indicated by immunoprecipitation of the helicase from crude extracts. No difference was observed in XP-C cells in intracellular localization of DNA helicase Q1, phosphorylation, and the interaction with other proteins as compared to HeLa cells.
Tada
S
S
Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Yanagisawa
J
J
Sonoyama
T
T
Miyajima
A
A
Seki
M
M
Ui
M
M
Enomoto
T
T
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D000918:Antibody Specificity; D004265:DNA Helicases / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D006367:HeLa Cells / Q000201:enzymology; D006801:Humans; D015151:Immunoblotting; D011233:Precipitin Tests; D053484:RecQ Helicases; D014983:Xeroderma Pigmentosum / Q000201:enzymology* / Q000235:genetics*
D000251:Adenosine Triphosphatases; C506725:RECQL protein, human; C506724:RecQ protein, E coli; D004265:DNA Helicases; D053484:RecQ Helicases