Mutational analysis of Escherichia coli topoisomerase IV. III. Identification of a region of ParE involved in covalent catalysis Journal Article
| Authors: | Bahng, S.; Mossessova, E.; Nurse, P.; Marians, K. J. |
| Article Title: | Mutational analysis of Escherichia coli topoisomerase IV. III. Identification of a region of ParE involved in covalent catalysis |
| Abstract: | The products of three dominant-negative alleles of parE, encoding the ATP-binding subunit of topoisomerase IV (Topo IV), were purified and their activities characterized when reconstituted with ParC to form Topo IV. The ability of the ParE E418K, ParE G419D, and ParE G442D mutant Topo IVs to bind DNA, hydrolyze ATP, and close their ATP-dependent clamp was relatively unaffected. However, their ability to relax negatively supercoiled DNA was compromised significantly. This could be attributed to severe defects in covalent complex formation between ParC and DNA. Thus, these residues, which are far from the active site Tyr of ParC, contribute to covalent catalysis. This indicates that a dramatic conformational rearrangement of the protein likely occurs subsequent to the binding of the G segment at the DNA gate and prior to its opening. |
| Keywords: | mutation; dna-binding proteins; nonhuman; mutant protein; protein conformation; allele; protein binding; alleles; bacterial proteins; escherichia coli; models, molecular; binding sites; catalysis; adenosine triphosphate; enzyme subunit; dna topoisomerases, type ii; dna topoisomerase iv; dna topoisomerase; dna supercoiling; dna, superhelical; norfloxacin; enzyme reconstitution; prokaryota; dna protein complex; negibacteria; priority journal; article |
| Journal Title: | Journal of Biological Chemistry |
| Volume: | 275 |
| Issue: | 6 |
| ISSN: | 0021-9258 |
| Publisher: | American Society for Biochemistry and Molecular Biology |
| Date Published: | 2000-02-11 |
| Start Page: | 4112 |
| End Page: | 4117 |
| Language: | English |
| DOI: | 10.1074/jbc.275.6.4112 |
| PUBMED: | 10660571 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | Export Date: 18 November 2015 -- Source: Scopus |
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