HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 279, Issue 41, 42794-42802, October 8, 2004

This Article Full Text Full Text (PDF) All Versions of this Article: 279/41/42794    most recent M405008200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Liu, J. L. Articles by Xi, X. G. Search for Related Content PubMed PubMed Citation Articles by Liu, J. L. Articles by Xi, X. G. Social Bookmarking                      What's this?

The Zinc Finger Motif of Escherichia coli RecQ Is Implicated in Both DNA Binding and Protein Folding^*

Jie Lin Liu, Pascal Rigolet, Shuo-Xing Dou, Peng-Ye Wang, and Xu Guang Xi

From the Laboratoire de Biotechnologies et Pharmacologie Génétique Appliquée CNRS UMR 8113, Ecole Normale Supérieure (ENS) Cachan, 61 avenue du Président Wilson, 94235 Cachan cedex, France and Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China

The RecQ family of DNA helicases has been shown to be important for the maintenance of genomic integrity. Mutations in human RecQ genes lead to genomic instability and cancer. Several RecQ family of helicases contain a putative zinc finger motif of the C₄ type at the C terminus that has been identified in the crystalline structure of RecQ helicase from Escherichia coli. To better understand the role of this motif in helicase from E. coli, we constructed a series of single mutations altering the conserved cysteines as well as other highly conserved residues. All of the resulting mutant proteins exhibited a high level of susceptibility to degradation, making functional analysis impossible. In contrast, a double mutant protein in which both cysteine residues Cys³⁹⁷ and Cys⁴⁰⁰ in the zinc finger motif were replaced by asparagine residues was purified to homogeneity. Slight local conformational changes were detected, but the rest of the mutant protein has a well defined tertiary structure. Furthermore, the mutant enzyme displayed ATP binding affinity similar to the wild-type enzyme but was severely impaired in DNA binding and in subsequent ATPase and helicase activities. These results revealed that the zinc finger binding motif is involved in maintaining the integrity of the whole protein as well as DNA binding. We also showed that the zinc atom is not essential to enzymatic activity.

Received for publication, May 5, 2004 , and in revised form, July 26, 2004.

^* This work was supported by the Centre National de la Recherche Scientifique (CNRS), the National Natural Science Foundation of China, and the Innovation Project of the Chinese Academy of Sciences. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

To whom correspondence should be addressed. Tel.: 33-1-47-40-68-92; Fax: 33-1-47-40-76-71; E-mail: xi{at}lbpa.ens-cachan.fr.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				B. Zhang, A.-h. Zhang, L. Chen, and X. G. Xi Inhibition of DNA Helicase, ATPase and DNA-Binding Activities of E. coli RecQ Helicase by Chemotherapeutic Agents J. Biochem., June 1, 2008; 143(6): 773 - 779. [Abstract] [Full Text] [PDF]

				M. P. Killoran and J. L. Keck Structure and function of the regulatory C-terminal HRDC domain from Deinococcus radiodurans RecQ Nucleic Acids Res., May 1, 2008; 36(9): 3139 - 3149. [Abstract] [Full Text] [PDF]

				H. Ren, S.-X. Dou, P. Rigolet, Y. Yang, P.-Y. Wang, M. Amor-Gueret, and X. G. Xi The arginine finger of the Bloom syndrome protein: its structural organization and its role in energy coupling Nucleic Acids Res., September 25, 2007; 35(18): 6029 - 6041. [Abstract] [Full Text] [PDF]

				M. P. Killoran and J. L. Keck Sit down, relax and unwind: structural insights into RecQ helicase mechanisms Nucleic Acids Res., September 10, 2006; 34(15): 4098 - 4105. [Abstract] [Full Text] [PDF]

				F. M. Hisama, V. A. Bohr, and J. Oshima WRN's Tenth Anniversary Sci. Aging Knowl. Environ., June 28, 2006; 2006(10): pe18 - pe18. [Abstract] [Full Text]

				M. P. Killoran and J. L. Keck Three HRDC Domains Differentially Modulate Deinococcus radiodurans RecQ DNA Helicase Biochemical Activity J. Biol. Chem., May 5, 2006; 281(18): 12849 - 12857. [Abstract] [Full Text] [PDF]

				J.-S. Hu, H. Feng, W. Zeng, G.-x. Lin, and X. G. Xi Solution structure of a multifunctional DNA- and protein-binding motif of human Werner syndrome protein PNAS, December 20, 2005; 102(51): 18379 - 18384. [Abstract] [Full Text] [PDF]

				J. W. Lee, R. Kusumoto, K. M. Doherty, G.-X. Lin, W. Zeng, W.-H. Cheng, C. von Kobbe, R. M. Brosh Jr., J.-S. Hu, and V. A. Bohr Modulation of Werner Syndrome Protein Function by a Single Mutation in the Conserved RecQ Domain J. Biol. Chem., November 25, 2005; 280(47): 39627 - 39636. [Abstract] [Full Text] [PDF]

				R.-b. Guo, P. Rigolet, L. Zargarian, S. Fermandjian, and X. G. Xi Structural and functional characterizations reveal the importance of a zinc binding domain in Bloom's syndrome helicase Nucleic Acids Res., June 1, 2005; 33(10): 3109 - 3124. [Abstract] [Full Text] [PDF]