1E0K

gp4d helicase from phage T7

Summary for 1E0K

• Entry DOI: 10.2210/pdb1e0k/pdb
• Related: 1B79 1CR0 1CR1 1CR2 1CR4 1E0J 1JWE
• Descriptor: DNA HELICASE (1 entity in total)
• Functional Keywords: helicase, atpase, dna replication
• Biological source: PHAGE T7
• Total number of polymer chains: 6
• Total formula weight: 190530.83

Authors

Singleton, M.R.,Sawaya, M.R.,Ellenberger, T.,Wigley, D.B. (deposition date: 2000-03-30, release date: 2000-06-09, Last modification date: 2024-05-08)

Primary citation

Singleton, M.R.,Sawaya, M.R.,Ellenberger, T.,Wigley, D.B.
Crystal Structure of T7 Gene 4 Ring Helicase Indicates a Mechanism for Sequential Hydrolysis of Nucleotides
Cell(Cambridge,Mass.), 101:589-, 2000

PubMed Abstract: We have determined the crystal structure of an active, hexameric fragment of the gene 4 helicase from bacteriophage T7. The structure reveals how subunit contacts stabilize the hexamer. Deviation from expected six-fold symmetry of the hexamer indicates that the structure is of an intermediate on the catalytic pathway. The structural consequences of the asymmetry suggest a "binding change" mechanism to explain how cooperative binding and hydrolysis of nucleotides are coupled to conformational changes in the ring that most likely accompany duplex unwinding. The structure of a complex with a nonhydrolyzable ATP analog provides additional evidence for this hypothesis, with only four of the six possible nucleotide binding sites being occupied in this conformation of the hexamer. This model suggests a mechanism for DNA translocation.

PubMed: 10892646
DOI: 10.1016/S0092-8674(00)80871-5

Experimental method

X-RAY DIFFRACTION (3.3 Å)