Hexameric ring structure of the N-terminal domain of Mycobacterium tuberculosis DnaB helicase.
Biswas, T., Tsodikov, O.V.(2008) FEBS J 275: 3064-3071
- PubMed: 18479467 
- DOI: https://doi.org/10.1111/j.1742-4658.2008.06460.x
- Primary Citation of Related Structures:  
2R5U - PubMed Abstract: 
Hexameric DnaB helicase unwinds the DNA double helix during replication of genetic material in bacteria. DnaB is an essential bacterial protein; therefore, it is an important potential target for antibacterial drug discovery. We report a crystal structure of the N-terminal region of DnaB from the pathogen Mycobacterium tuberculosis (MtDnaBn), determined at 2.0 A resolution. This structure provides atomic resolution details of formation of the hexameric ring of DnaB by two distinct interfaces. An extensive hydrophobic interface stabilizes a dimer of MtDnaBn by forming a four-helix bundle. The other, less extensive, interface is formed between the dimers, connecting three of them into a hexameric ring. On the basis of crystal packing interactions between MtDnaBn rings, we suggest a model of a helicase-primase complex that explains previously observed effects of DnaB mutations on DNA priming.
Organizational Affiliation: 
Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA.