Structural asymmetry governs the assembly and GTPase activity of McrBC restriction complexes
| العنوان: | Structural asymmetry governs the assembly and GTPase activity of McrBC restriction complexes |
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| المؤلفون: | Hiroshi Suzuki, Yiming Niu, Christopher J. Hosford, Thomas Walz, Joshua S. Chappie |
| المصدر: | Nature Communications, Vol 11, Iss 1, Pp 1-17 (2020) Nature Communications |
| بيانات النشر: | Cold Spring Harbor Laboratory, 2020. |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | 0301 basic medicine, G protein, Hydrolases, Science, Lysine, DNA restriction-modification enzymes, General Physics and Astronomy, GTPase, DNA Restriction-Modification Enzymes, DNA-binding protein, General Biochemistry, Genetics and Molecular Biology, Article, GTP Phosphohydrolases, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, GTP-binding protein regulators, Bacterial Proteins, DNA-binding proteins, Asparagine, lcsh:Science, 030304 developmental biology, 0303 health sciences, Nuclease, Multidisciplinary, biology, Hydrolysis, 030302 biochemistry & molecular biology, Cryoelectron Microscopy, Thermococcus gammatolerans, Active site, General Chemistry, DNA Restriction Enzymes, biology.organism_classification, Archaea, 3. Good health, Cell biology, Thermococcus, 030104 developmental biology, chemistry, biology.protein, lcsh:Q, Guanosine Triphosphate, 030217 neurology & neurosurgery, DNA |
| الوصف: | McrBC complexes are motor-driven nucleases functioning in bacterial self-defense by cleaving foreign DNA. The GTP-specific AAA + protein McrB powers translocation along DNA and its hydrolysis activity is stimulated by its partner nuclease McrC. Here, we report cryo-EM structures of Thermococcus gammatolerans McrB and McrBC, and E. coli McrBC. The McrB hexamers, containing the necessary catalytic machinery for basal GTP hydrolysis, are intrinsically asymmetric. This asymmetry directs McrC binding so that it engages a single active site, where it then uses an arginine/lysine-mediated hydrogen-bonding network to reposition the asparagine in the McrB signature motif for optimal catalytic function. While the two McrBC complexes use different DNA-binding domains, these contribute to the same general GTP-recognition mechanism employed by all G proteins. Asymmetry also induces distinct inter-subunit interactions around the ring, suggesting a coordinated and directional GTP-hydrolysis cycle. Our data provide insights into the conserved molecular mechanisms governing McrB family AAA + motors. The bacterial defense system McrBC is a two-component motor-driven nuclease complex that cleaves foreign DNA. Here, the authors present the structures of the GTP-specific AAA + motor protein McrB and two McrBC complexes and discuss the molecular mechanism of how McrC binding stimulates McrB GTP hydrolysis. |
| اللغة: | English |
| DOI: | 10.1101/2020.01.30.927467 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::63cf325efd02590824daec070ba7596a |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....63cf325efd02590824daec070ba7596a |
| قاعدة البيانات: | OpenAIRE |
| DOI: | 10.1101/2020.01.30.927467 |
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