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-Structure paper
Title | Structure-based mechanism for activation of the AAA+ GTPase McrB by the endonuclease McrC. |
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Journal, issue, pages | Nat Commun, Vol. 10, Issue 1, Page 3058, Year 2019 |
Publish date | Jul 11, 2019 |
Authors | Neha Nirwan / Yuzuru Itoh / Pratima Singh / Sutirtha Bandyopadhyay / Kutti R Vinothkumar / Alexey Amunts / Kayarat Saikrishnan / |
PubMed Abstract | The AAA+ GTPase McrB powers DNA cleavage by the endonuclease McrC. The GTPase itself is activated by McrC. The architecture of the GTPase and nuclease complex, and the mechanism of their activation ...The AAA+ GTPase McrB powers DNA cleavage by the endonuclease McrC. The GTPase itself is activated by McrC. The architecture of the GTPase and nuclease complex, and the mechanism of their activation remained unknown. Here, we report a 3.6 Å structure of a GTPase-active and DNA-binding deficient construct of McrBC. Two hexameric rings of McrB are bridged by McrC dimer. McrC interacts asymmetrically with McrB protomers and inserts a stalk into the pore of the ring, reminiscent of the γ subunit complexed to αβ of F-ATPase. Activation of the GTPase involves conformational changes of residues essential for hydrolysis. Three consecutive nucleotide-binding pockets are occupied by the GTP analogue 5'-guanylyl imidodiphosphate and the next three by GDP, which is suggestive of sequential GTP hydrolysis. |
External links | Nat Commun / PubMed:31296862 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.6 - 4.8 Å |
Structure data | EMDB-0310, PDB-6hz4: EMDB-0311, PDB-6hz5: EMDB-0312, PDB-6hz6: EMDB-0313, PDB-6hz7: |
Chemicals | ChemComp-GNP: ChemComp-MG: ChemComp-GDP: |
Source |
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Keywords | DNA BINDING PROTEIN / AAA+ superfamily / restriction enzyme |