1wp5 | pdb_00001wp5
Crystal structure of the C-terminal domain of DNA topoisomerase IV
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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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