The conformational changes coupling ATP hydrolysis and translocation in a bacterial DnaB helicase

• Published in: Nature communications Vol. 10; no. 1; pp. 31 - 11
• Main Authors: Wiegand, Thomas, Cadalbert, Riccardo, Lacabanne, Denis, Timmins, Joanna, Terradot, Laurent, Böckmann, Anja, Meier, Beat H
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 03.01.2019; Nature Publishing Group UK; Nature Portfolio
• Subjects: Adenosine diphosphate; Adenosine Diphosphate - metabolism; Adenosine triphosphate; Adenosine Triphosphate - analogs & derivatives; Adenosine Triphosphate - metabolism; Amino acids; AMP; Analytical chemistry; ATP; Bacterial Physiological Phenomena; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; Biochemistry, Molecular Biology; Chemical Sciences; Deoxyribonucleic acid; DNA; DNA biosynthesis; DNA helicase; DNA Replication - physiology; DNA, Single-Stranded - metabolism; DnaB helicase; DnaB Helicases - chemistry; DnaB Helicases - metabolism; Hydrolysis; Life Sciences; Magnetic resonance spectroscopy; NMR spectroscopy; Nuclear Magnetic Resonance, Biomolecular; Protein Conformation; Proteins; Replication; Spectrum analysis; Structural Biology; Translocation
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-07968-3

DnaB helicases are motor proteins that couple ATP-hydrolysis to the loading of the protein onto DNA at the replication fork and to translocation along DNA to separate double-stranded DNA into single strands during replication. Using a network of conformational states, arrested by nucleotide mimics, we herein characterize the reaction coordinates for ATP hydrolysis, DNA loading and DNA translocation using solid-state NMR spectroscopy. AMP-PCP is used as pre-hydrolytic, ADP:AlF as transition state, and ADP as post-hydrolytic ATP mimic. P and C NMR spectra reveal conformational and dynamic responses to ATP hydrolysis and the resulting DNA loading and translocation with single amino-acid resolution. This allows us to identify residues guiding the DNA translocation process and to explain the high binding affinities for DNA observed for ADP:AlF , which turns out to be optimally preconfigured to bind DNA.