کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1925837 1536416 2011 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Cloning and biochemical characterization of Staphylococcus aureus type IA DNA topoisomerase comprised of distinct five domains
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Cloning and biochemical characterization of Staphylococcus aureus type IA DNA topoisomerase comprised of distinct five domains
چکیده انگلیسی

DNA topoisomerases play critical roles in regulating DNA topology and are essential enzymes for cell survival. In this study, a gene encoding type IA DNA topoisomerase was cloned from Staphylococcus aureus (S. aureus) sp. strain C-66, and the biochemical properties of recombinant enzyme was characterized. The nucleotide sequence analysis showed that the cloned gene contained an open reading frame (2070 bp) that could encode a polypeptide of 689 amino acids. The cloned gene actually produced 79.1 kDa functional enzyme (named Sau-TopoI) in Escherichia coli (E. coli). Sau-TopoI enzyme purified from E. coli showed ATP-independent and Mg2+-dependent manners for relaxing negatively supercoiled DNA. The relaxation activity of Sau-TopoI was inhibited by camptothecin, but not by nalidixic acid and etoposide. Cleavage site mapping showed that the enzyme could preferentially bind to and cleave the sequence GGNN↓CAT (N and ↓ represent any nucleotide and cleavage site, respectively). All these results suggest that the purified enzyme is type IA DNA topoisomerase. In addition, domain mapping analysis showed that the enzyme was composed of conserved four domains (I through IV), together with a variable C-terminal region containing a unique domain V.

Research highlights
► Cloning and expression of a novel Staphylococcal type IA DNA topoisomerase.
► Characterization of biochemical properties of Staphylococcal type IA DNA topoisomerase expressed in E. coli.
► Identification of sequence recognition and cleavage site for Staphylococcal type IA DNA topoisomerase.
► Domain mapping of Staphylococcal type IA DNA topoisomerase.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 508, Issue 1, 1 April 2011, Pages 78–86
نویسندگان
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