دورية أكاديمية
Mutagenesis of E477 or K505 in the B' domain of human topoisomerase II beta increases the requirement for magnesium ions during strand passage.
| العنوان: | Mutagenesis of E477 or K505 in the B' domain of human topoisomerase II beta increases the requirement for magnesium ions during strand passage. |
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| المؤلفون: | West KL; Department of Biochemistry and Genetics, The Medical School, The University of Newcastle Upon Tyne, Newcastle Upon Tyne NE2 4HH, UK., Meczes EL, Thorn R, Turnbull RM, Marshall R, Austin CA |
| المصدر: | Biochemistry [Biochemistry] 2000 Feb 15; Vol. 39 (6), pp. 1223-33. |
| نوع المنشور: | Journal Article |
| اللغة: | English |
| بيانات الدورية: | Publisher: American Chemical Society Country of Publication: United States NLM ID: 0370623 Publication Model: Print Cited Medium: Print ISSN: 0006-2960 (Print) Linking ISSN: 00062960 NLM ISO Abbreviation: Biochemistry Subsets: MEDLINE |
| أسماء مطبوعة: | Original Publication: Washington, American Chemical Society. |
| مواضيع طبية MeSH: | Mutagenesis, Site-Directed*, DNA/*chemistry , DNA Topoisomerases, Type II/*genetics , Magnesium/*chemistry , Peptide Fragments/*genetics, Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Catalysis ; Cations, Divalent/chemistry ; Cations, Divalent/metabolism ; DNA/genetics ; DNA/metabolism ; DNA Topoisomerases, Type II/chemistry ; DNA Topoisomerases, Type II/metabolism ; DNA, Fungal/chemistry ; DNA, Fungal/genetics ; DNA, Fungal/metabolism ; DNA, Superhelical/chemistry ; DNA, Superhelical/genetics ; DNA, Superhelical/metabolism ; DNA-Binding Proteins ; Genetic Complementation Test ; Glutamic Acid/genetics ; Humans ; Hydrolysis ; Lysine/genetics ; Molecular Sequence Data ; Peptide Fragments/chemistry ; Peptide Fragments/metabolism ; Recombinant Proteins/chemistry ; Recombinant Proteins/metabolism ; Saccharomyces cerevisiae/genetics |
| مستخلص: | A type II topoisomerase is essential for decatenating DNA replication products, and it accomplishes this task by passing one DNA duplex through a transient break in a second duplex. The B' domain of topoisomerase II contains three highly conserved motifs, EGDSA, PL(R/K)GK(I/L/M)LNVR, and IMTD(Q/A)DXD. We have investigated these motifs in topoisomerase II beta by mutagenesis, and report that they play a critical role in establishing the DNA cleavage-religation equilibrium. In addition, the mutations E477Q (EGDSA) and K505E (PLRGKILNVR) increase the optimal magnesium ion concentration for strand passage, without affecting the Mg(2+) dependence of ATP hydrolysis. It is likely that the binding affinity of the magnesium ion(s) specifically required for DNA cleavage has been reduced by these mutations. The crystal structure of yeast topo II indicates that residues E477 and K505 may help to position the three aspartate residues of the IMTD(Q/A)DXD motif for magnesium ion coordination, and we propose two possible locations for the magnesium ion binding site(s). These observations are consistent with a previous model in which the B' domain is positioned such that these acidic residues lie next to the active site tyrosine residue. A magnesium ion bound by these aspartate residues could therefore mediate the DNA cleavage-religation reaction. |
| المشرفين على المادة: | 0 (Cations, Divalent) 0 (DNA, Fungal) 0 (DNA, Superhelical) 0 (DNA-Binding Proteins) 0 (Peptide Fragments) 0 (Recombinant Proteins) 3KX376GY7L (Glutamic Acid) 8L70Q75FXE (Adenosine Triphosphate) 9007-49-2 (DNA) EC 5.99.1.3 (DNA Topoisomerases, Type II) I38ZP9992A (Magnesium) K3Z4F929H6 (Lysine) |
| تواريخ الأحداث: | Date Created: 20000224 Date Completed: 20000313 Latest Revision: 20190613 |
| رمز التحديث: | 20221213 |
| DOI: | 10.1021/bi991328b |
| PMID: | 10684600 |
| قاعدة البيانات: | MEDLINE |
Find this issue from the American Chemical Society | تدمد: | 0006-2960 |
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| DOI: | 10.1021/bi991328b |