In:
Biochemical Journal, Portland Press Ltd., Vol. 412, No. 3 ( 2008-06-15), p. 425-433
Abstract:
RecQ family helicases, functioning as caretakers of genomic integrity, contain a zinc-binding motif which is highly conserved among these helicases, but does not have a substantial structural similarity with any other known zinc-finger folds. In the present study, we show that a truncated variant of the human RECQ5β helicase comprised of the conserved helicase domain only, a splice variant named RECQ5α, possesses neither ATPase nor DNA-unwinding activities, but surprisingly displays a strong strand-annealing activity. In contrast, fragments of RECQ5β including the intact zinc-binding motif, which is located immediately downstream of the helicase domain, exhibit much reduced strand-annealing activity but are proficient in DNA unwinding. Quantitative measurements indicate that the regulatory role of the zinc-binding motif is achieved by enhancing the DNA-binding affinity of the enzyme. The novel intramolecular modulation of RECQ5β catalytic activity mediated by the zinc-binding motif may represent a universal regulation mode for all RecQ family helicases.
Type of Medium:
Online Resource
ISSN:
0264-6021
,
1470-8728
Language:
English
Publisher:
Portland Press Ltd.
Publication Date:
2008
detail.hit.zdb_id:
1473095-9
SSG:
12
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