6UT8
Refined half-complex from tetradecameric assembly of Thermococcus gammatolerans McrB AAA+ hexamers with bound McrC
Summary for 6UT8
| Entry DOI | 10.2210/pdb6ut8/pdb |
| Related | 6UT3 |
| EMDB information | 20871 |
| Descriptor | GTPase subunit of restriction endonuclease, McrBC 5-methylcytosine restriction system component, GUANOSINE-5'-DIPHOSPHATE, ... (5 entities in total) |
| Functional Keywords | endonuclease, aaa protein, gtpase, methylation-dependent restriction, dna binding protein |
| Biological source | Thermococcus gammatolerans More |
| Total number of polymer chains | 7 |
| Total formula weight | 358351.94 |
| Authors | Niu, Y.,Suzuki, H.,Hosford, C.J.,Chappie, J.S.,Walz, T. (deposition date: 2019-10-29, release date: 2020-10-21, Last modification date: 2024-03-06) |
| Primary citation | Niu, Y.,Suzuki, H.,Hosford, C.J.,Walz, T.,Chappie, J.S. Structural asymmetry governs the assembly and GTPase activity of McrBC restriction complexes. Nat Commun, 11:5907-5907, 2020 Cited by PubMed Abstract: 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. PubMed: 33219217DOI: 10.1038/s41467-020-19735-4 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.68 Å) |
Structure validation
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