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Drug-Resistant Bacterial Topoisomerases

We offer various quinolone- and coumarin-resistant topoisomerase mutants from a range of organisms including E. coli, and S. aureus. The proteins can be supplied as separate subunits or as reconstituted enzyme. Typically the quinolone-resistant mutants confer 50-100 X more resistance to fluoroquinolones than the wild-type. We have more than 25 mutants in different topoisomerases and can make other mutants as requested. For the currently available mutants please see the table below:

Organism/Subunit Mutation Resistance/Activity affected
E. coli gyrase    
GyrA S83T,C,L,W Quinolone
GyrA S83A/D87A double Quinolone
GyrA D87A, H, K Quinolone
GyrA D82N Quinolone
GyrA R91Q Simocyclinone
GyrA A84Y Simocyclinone
GyrA A84R Simocyclinone
GyrA K42A Simocyclinone
GyrA M120P Simocyclinone
GyrA M120K NXL101
GyrA L387F Exit gate mutant
GyrA K465A Exit gate mutant
GyrA55 L387F   A55 Exit gate mutant
GyrA55 K465A   A55 Exit gate mutant
GyrA C194A/C592A/C716A/C792A/G81C One cysteine only
GyrA L3461CL463C Exit gate mutant
GyrB W751R MicrocinB17
GyrB24 R136 Coumarin
GyrB D426N Quinolone
GyrB K110A  
GyrB K103A K110A ATP coupling
GyrB43 loopless mutant' ATP coupling
S. aureus gyrase    
GyrA D83N Quinolone
GyrA S84L Quinolone
GyrB T173N Novobiocin
GyrB G35S  
GyrB S128F  
GyrB R144I  
M. tuberculosis gyrase    
GyrA D94G Novobiocin
GyrB T539N Quinolone
GyrB A53S       
GyrB A57V      
GyrB V125L        
GyrB S169A     
A. baumanni gyrase    
GyrB R150C  
S. pneumoniae Topo IV    
ParC S79F  
ParC S80F  
E. coli Topo IV    
ParC S80I  
S. aureus Topo IV    
ParC/GrlA S80F  

Please contact us directly for more information or to request pricing!

We have a range of products that will help your drug discovery efforts, whether you are looking for novel anti-infectives, or new anti-cancer compounds, we have a range of target enzymes, available with and without their substrates, in easy to use kits. We also supply different topological isoforms of our DNA substrates.

Don't see your required enzyme? Contact us to see if we can make it for you or visit our Custom Proteins page! 

Not doing drug discovery? Our enzymes and DNA substrates are of extremely high purity and quality, perfect for reliable results!

All of our enzymes can be supplied in large or bulk quantities or at higher concentrations. Please contact us for a quote!

Likewise, if you require enzymes with particular specifications (e.g. low endotoxin, DNase or RNase free, low bioburden etc.), please contact us.


You can contact us on +44(0) 1603 673590 or +44(0) 1603 673591, at [email protected] or by visiting our contact us page to discuss your requirements.

Need help?
Call us on +44 (0) 1603 673591
Email on [email protected]

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