User:Isabelle Kressy/Sandbox 1
From Proteopedia
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Quinolone(Clinafloxacin)-DNA cleavage complex of type IV topoisomerase from S. pneumoniae
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Function
Topoisomerase IV in S. pneumoniae is a paralogue of type II topoisomerase. Its main function is to regulate the level of DNA supercoiling within the cell so that replication, transcription, and repair can take place [1].
Type II topoisomerases undergo a strand-passage mechanism to remove supercoiling and disentangle chromosomes. These enzymes cleave both strands of DNA and then pass a second duplex through the break using ATP. The cleaved strands are ligated together again and the two products are released from the enzyme [2].
Structural Description
The active site is a tetramer made up of and subunits. The ParC subunit contains an N-terminal DNA breakage-reunion domain, which is linked to C-terminal β-pinwheel domains. This favors the passage of DNA and DNA unlinking from the complex. In contrast, the N-terminal of the ParE subunits forms the ATPase domain. Topoisomerase IV forms a complex with gyrase and works in tandem to remove DNA supercoiling and disentangle chromosomes.
Structure Insights
Evolutionarily Related Proteins
Available Structures
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References
- ↑ Laponogov I, Pan XS, Veselkov DA, Cirz RT, Wagman A, Moser HE, Fisher LM, Sanderson MR. Exploring the active site of the Streptococcus pneumoniae topoisomerase IV-DNA cleavage complex with novel 7,8-bridged fluoroquinolones. Open Biol. 2016 Sep;6(9). pii: rsob.160157. doi: 10.1098/rsob.160157. PMID:27655731 doi:http://dx.doi.org/10.1098/rsob.160157
- ↑ Laponogov I, Veselkov DA, Crevel IM, Pan XS, Fisher LM, Sanderson MR. Structure of an 'open' clamp type II topoisomerase-DNA complex provides a mechanism for DNA capture and transport. Nucleic Acids Res. 2013 Aug 21. PMID:23965305 doi:10.1093/nar/gkt749
