کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2146105 1548310 2016 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Site-directed mutants of human RECQ1 reveal functional importance of the zinc binding domain
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی تحقیقات سرطان
پیش نمایش صفحه اول مقاله
Site-directed mutants of human RECQ1 reveal functional importance of the zinc binding domain
چکیده انگلیسی


• The zinc binding motif in the RQC domain of RECQ1 is a key structural element.
• Cysteine residues that coordinate zinc binding in RECQ1 are critical for the ATPase and helicase activities.
• RECQ1 mutants that lack zinc binding retain DNA binding and annealing activities.
• Conserved cysteine residues contribute differentially to the RECQ1 structure and functions.

RecQ helicases are a highly conserved family of ATP-dependent DNA-unwinding enzymes with key roles in DNA replication and repair in all kingdoms of life. The RECQ1 gene encodes the most abundant RecQ homolog in humans. We engineered full-length RECQ1 harboring point mutations in the zinc-binding motif (amino acids 419–480) within the conserved RecQ-specific-C-terminal (RQC) domain known to be critical for diverse biochemical and cellular functions of RecQ helicases. Wild-type RECQ1 contains a zinc ion. Substitution of three of the four conserved cysteine residues that coordinate zinc severely impaired the ATPase and DNA unwinding activities but retained DNA binding and single strand DNA annealing activities. Furthermore, alteration of these residues attenuated zinc binding and significantly changed the overall conformation of full-length RECQ1 protein. In contrast, substitution of cysteine residue at position 471 resulted in a wild-type like RECQ1 protein. Differential contribution of the conserved cysteine residues to the structure and functions of the RECQ1 protein is also inferred by homology modeling. Overall, our results indicate that the zinc binding motif in the RQC domain of RECQ1 is a key structural element that is essential for the structure-functions of RECQ1. Given the recent association of RECQ1 mutations with breast cancer, these results will contribute to understanding the molecular basis of RECQ1 functions in cancer etiology.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis - Volume 790, August 2016, Pages 8–18
نویسندگان
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