EMD-0313
Structure of McrBC without DNA binding domains (Class 3)
EMD-0313
Single-particle4.3 Å
Deposition: 22/10/2018Map released: 24/07/2019
Last modified: 15/05/2024
Sample Organism:
Escherichia coli (strain K12)
Sample: McrB and McrC complex without DNA binding domains
Fitted models: 6hz7 (Avg. Q-score: 0.314)
Deposition Authors: Itoh Y
,
Nirwan N
Sample: McrB and McrC complex without DNA binding domains
Fitted models: 6hz7 (Avg. Q-score: 0.314)
Deposition Authors: Itoh Y
,
Nirwan N
Structure-based mechanism for activation of the AAA+ GTPase McrB by the endonuclease McrC.
Nirwan N ,
Itoh Y ,
Singh P,
Bandyopadhyay S,
Vinothkumar KR ,
Amunts A ,
Saikrishnan K
(2019) Nat Commun , 10 , 3058 - 3058
,
Itoh Y ,
Singh P,
Bandyopadhyay S,
Vinothkumar KR ,
Amunts A ,
Saikrishnan K
(2019) Nat Commun , 10 , 3058 - 3058
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 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 α3β3 of F1-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.
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 α3β3 of F1-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.