1wp5
From Proteopedia
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Crystal structure of the C-terminal domain of DNA topoisomerase IV
Overview
Bacteria possess two closely related yet functionally distinct essential, type IIA topoisomerases (Topos). DNA gyrase supports replication and, transcription with its unique supercoiling activity, whereas Topo IV, preferentially relaxes (+) supercoils and is a decatenating enzyme, required for chromosome segregation. Here we report the crystal structure, of the C-terminal domain of Topo IV ParC subunit (ParC-CTD) from Bacillus, stearothermophilus and provide a structure-based explanation for how Topo, IV and DNA gyrase execute distinct activities. Although the topological, connectivity of ParC-CTD is similar to the recently determined CTD, structure of DNA gyrase GyrA subunit (GyrA-CTD), ParC-CTD surprisingly, folds as a previously unseen broken form of a six-bladed beta-propeller., Propeller breakage is due to the absence of a DNA gyrase-specific GyrA box, motif, resulting in the reduction of curvature of the proposed DNA binding, region, which explains why ParC-CTD is less efficient than GyrA-CTD in, mediating DNA bending, a difference that leads to divergent activities of, the two homologous enzymes. Moreover, we found that the topology of the, propeller blades observed in ParC-CTD and GyrA-CTD can be achieved from a, concerted beta-hairpin invasion-induced fold change event of a canonical, six-bladed beta-propeller; hence, we proposed to name this new fold as, "hairpin-invaded beta-propeller" to highlight the high degree of, similarity and a potential evolutionary linkage between them. The possible, role of ParC-CTD as a geometry facilitator during various catalytic events, and the evolutionary relationships between prokaryotic type IIA Topos have, also been discussed according to these new structural insights.
About this Structure
1WP5 is a Protein complex structure of sequences from Geobacillus stearothermophilus. Full crystallographic information is available from OCA.
Reference
Structure of the topoisomerase IV C-terminal domain: a broken beta-propeller implies a role as geometry facilitator in catalysis., Hsieh TJ, Farh L, Huang WM, Chan NL, J Biol Chem. 2004 Dec 31;279(53):55587-93. Epub 2004 Oct 4. PMID:15466871
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