1z5c
From Proteopedia
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Topoisomerase VI-B, ADP Pi bound dimer form
Overview
GHL proteins are functionally diverse enzymes defined by the presence of a conserved ATPase domain that self-associates to trap substrate upon nucleotide binding. The structural states adopted by these enzymes during nucleotide hydrolysis and product release, and their consequences for enzyme catalysis, have remained unclear. Here, we have determined a complete structural map of the ATP turnover cycle for topoVI-B, the ATPase subunit of the archaeal GHL enzyme topoisomerase VI. With this ensemble of structures, we show that significant conformational changes in the subunit occur first upon ATP binding, and subsequently upon release of hydrolyzed P(i). Together, these data provide a structural framework for understanding the role of ATP hydrolysis in the type II topoisomerase reaction. Our results also suggest that the GHL ATPase module is a molecular switch in which ATP hydrolysis serves as a prerequisite but not a driving force for substrate-dependent structural transitions in the enzyme.
About this Structure
1Z5C is a Single protein structure of sequence from Sulfolobus shibatae with , and as ligands. Active as DNA topoisomerase (ATP-hydrolyzing), with EC number 5.99.1.3 Full crystallographic information is available from OCA.
Reference
Structural dissection of ATP turnover in the prototypical GHL ATPase TopoVI., Corbett KD, Berger JM, Structure. 2005 Jun;13(6):873-82. PMID:15939019
Page seeded by OCA on Thu Feb 21 16:12:20 2008
