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Protein / target

DNA topoisomerase 4 subunit B

parEP20083Escherichia coli (strain K12)Swiss-Prot
UniProt: P20083NCBI Gene: 93778963
30
Clinical trials
2
Drugs targeting

Protein at a glance

Biological role

Metal ion binding

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function overview

Topoisomerase IV is essential for chromosome segregation; it is the principal protein responsible for decatenating newly replicated chromosomes.

View complete UniProt function annotation

Topoisomerase IV is essential for chromosome segregation; it is the principal protein responsible for decatenating newly replicated chromosomes (PubMed:9334322). It relaxes supercoiled DNA (PubMed:15105144, PubMed:21300644, PubMed:23294697, PubMed:23352267). MukB stimulates the relaxation activity of topoisomerase IV and also has a modest effect on decatenation (PubMed:20921377)

Domains and Gene Ontology detail (13)

Domains & features

Toprim

Gene Ontology

  • Cchromosome
  • Ccytosol
  • FATP binding
  • FDNA binding
  • FDNA topoisomerase type II (double strand cut, ATP-hydrolyzing) activity
  • Fmetal ion binding
  • Pchromosome organization
  • Pchromosome segregation
  • PDNA topological change
  • Pplasmid partitioning
  • Presponse to antibiotic
  • Psister chromatid cohesion

630 aa · 70 kDa

Approved medicines with mapped indications

2 medicines · 7 areas

Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.

Bacterial Infections2 medicines
Ciprofloxacinnorfloxacin
Eye Infections2 medicines
Ciprofloxacinnorfloxacin
Gonorrhea1 medicine
Ciprofloxacin
Infections1 medicine
Ciprofloxacin
Sinusitis1 medicine
Ciprofloxacin
Typhoid Fever1 medicine
Ciprofloxacin
Urinary Tract Infections1 medicine
Ciprofloxacin

Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.

Drugs targeting this protein

2

How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.

Ciprofloxacin
Inhibitor

Topoisomerase IV inhibitor

Indicated for Bacterial Infections, Eye Infections, Gonorrhea, Infections

Acts on a complex — shared with parC · 1 of 4 recorded protein targets

norfloxacin
Inhibitor

Topoisomerase IV inhibitor

Indicated for Bacterial Infections, Eye Infections

Acts on a complex — shared with parC · 1 of 4 recorded protein targets

ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.

Clinical trials

30

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.

Ciprofloxacin Versus Ceftazidime as Empirical Therapy of High-Risk Neutropenic Fever in Children With Hematologic Malignancies : A Randomized Controlled TrialPHASE4

RECRUITING · via Ciprofloxacin · NCT07016165

Comparative Study of Norfloxacin Versus Norfloxacin With Itopride in Secondary Prophylaxis of Spontaneous Bacterial PeritonitisPHASE3

RECRUITING · via norfloxacin · NCT04161768

REINFORCE - Reducing Infection-related Readmissions Following Cystectomy. a Multicentre Randomised Clinical Trial Testing Superiority of Individualised Targeted Antibiotic Prophylaxis Over Empiric Prophylaxis At Ureteral Stent Removal to Reduce Infection-related Readmissions Following Cystectomy.PHASE4

RECRUITING · via Ciprofloxacin · NCT06709196

CAT BITE Antibiotic Prophylaxis and Durations for the Hand/Forearm (CATBITE): A Prospective, Randomized, Placebo-controlled, Double-blinded, Clinical TrialPHASE4

RECRUITING · via Ciprofloxacin · NCT05846399

View all trials (26)
Oral Antimicrobial Treatment vs. Outpatient Parenteral for Infective EndocarditisPHASE4

RECRUITING · via Ciprofloxacin · NCT05398679

Prophylactic Antibiotics During Treatment of Idiopathic Overactive Bladder With Intradetrusor onabotulinumtoxinA for the Reduction of Postoperative UTI: a Randomized Blinded Placebo-controlled TrialPHASE4

RECRUITING · via Ciprofloxacin · NCT04444440

Pancreatic Cancer First-line NALIRIFOX Optimization With 5-FU Maintenance and Role of Antibiotics and Microbiota Exploration in Second-line Treatment - A Non-comparative, Randomized Phase II PANORAMIX GERCOR G-116 PRODIGE 105 Study.PHASE2

NOT_YET_RECRUITING · via Ciprofloxacin · NCT07028424

Effectiveness of Ciprofloxacin Intralesional Injection in the Treatment of Cutaneous Leishmaniasis Compared to Sodium Stibogluconate: a Parallel Groups Comparative TrialPHASE2

RECRUITING · via Ciprofloxacin · NCT06798402

Prophylactic Antibiotics Following Treatment of Neurogenic Overactive Bladder With Intradetrusor onabotulinumtoxinA for the Reduction of Postoperative UTI: a Randomized Blinded Placebo-controlled TrialPHASE2

RECRUITING · via Ciprofloxacin · NCT04791579

PROMIZE: A Phase I/II Trial to Assess the Safety, Tolerability and Preliminary Anti-tumour Activity of Oral Combination Antibiotic Therapy to Modulate the Microbiome in Combination With Enzalutamide With Metastatic Castration Resistant Prostate Cancer (mCRPC).PHASE1/PHASE2

RECRUITING · via Ciprofloxacin · NCT06126731

Pilot Study of Gut Microbiome Modulation to Enable Efficacy of Neoadjuvant Checkpoint-based Immunotherapy Following Chemotherapy in Pancreatic AdenocarcinomaPHASE2

RECRUITING · via Ciprofloxacin · NCT05462496

Safety and Feasibility of a Shigella Sonnei 53G Controlled Human Infection Model in Kenyan Adults: a Dose Finding and Dose Verification StudyPHASE1

RECRUITING · via Ciprofloxacin · NCT05959616

Collaborative Urological Prosthetics Investigation Directive Research GroupEARLY_PHASE1

ACTIVE_NOT_RECRUITING · via Ciprofloxacin · NCT05100654

A Pilot Study of Ciprofloxacin Plus Gemcitabine and Nab-Paclitaxel Chemotherapy in Patients With Metastatic Pancreatic Ductal Adenocarcinoma.PHASE1

ACTIVE_NOT_RECRUITING · via Ciprofloxacin · NCT04523987

CiproPAL (Ciprofloxacin Prophylaxis in Acute Leukaemia): A Randomised Trial to Assess the Use of Ciprofloxacin Prophylaxis to Prevent Bacterial Infection in Children Treated on the Induction Phase of the ALLTogether-1 Treatment ProtocolNA

ACTIVE_NOT_RECRUITING · via Ciprofloxacin · NCT04678869

Evaluation of SpeeDx's Ciprofloxacin gyrA Assay for Clinical Care of STD Clinic Patients With Neisseria GonorrheaNA

RECRUITING · via Ciprofloxacin · NCT05286931

Efficacy and Safety of tobRamycin Inhalation Solution for Pseudomonas AeruginoSa Eradication in Bronchiectasis (ERASE): a Multi-center, 2×2 Factorial Randomized, Double-blind, Placebo-controlled TrialPHASE4

COMPLETED · via Ciprofloxacin · NCT06093191

Does Post-operative Antibiotic Prophylaxis Reduce Urinary Tract Infection Rates After Holmium Laser Enucleation of Prostate? a Prospective Randomized Multi-center StudyPHASE4

WITHDRAWN · via Ciprofloxacin · NCT05274672

Early Versus Late Stopping of Antibiotics in Children With Cancer and High-risk Febrile NeutropeniaPHASE4

COMPLETED · via Ciprofloxacin · NCT04948463

Comparative Study Between Norfloxacin, Nitazoxanide and Colistin As Secondary Prophylactic Agents for Spontaneous Bacterial PeritonitisPHASE4

COMPLETED · via norfloxacin · NCT06827756

An Open Label Randomised Controlled Trial of Azithromycin Versus Ciprofloxacin for the Treatment of Children Hospitalised With Dysentery in Ho Chi Minh City, VietnamPHASE4

COMPLETED · via Ciprofloxacin · NCT03854929

Cluster-randomized Trial to Evaluate the Impact of Ciprofloxacin Prophylaxis as a Response to a Meningococcal Meningitis EpidemicPHASE4

WITHDRAWN · via Ciprofloxacin · NCT03431675

Otiprio Versus Ciprodex to Reduce Tympanostomy Tube FailurePHASE4

WITHDRAWN · via Ciprofloxacin · NCT03347461

A Multicenter Randomized Controlled Trial Assessing the Efficacy of Antimicrobial Prophylaxis for Extracorporeal Shock Wave Lithotripsy on Reducing Urinary Tract InfectionPHASE4

COMPLETED · via Ciprofloxacin · NCT03692715

Noroxin Efficacy and Safety TrialPHASE4

UNKNOWN · via norfloxacin · NCT03506256

The Effect of Rectal Swab Culture-guided Antimicrobial Prophylaxis in Men Undergoing Prostate Biopsy on Infectious Complications and Cost of Care: A Randomized Controlled Trial in the Netherlands.PHASE4

COMPLETED · via Ciprofloxacin · NCT03228108

Antimicrobial Treatment in Patients With Ventilator-associated Tracheobronchitis: a Prospective Randomized Placebo-controlled Double-blind Multicenter TrialPHASE4

TERMINATED · via Ciprofloxacin · NCT03012360

Targeted AntiBiotics for Chronic Pulmonary Disease: Can Targeted Antibiotic Therapy Improve the Prognosis of Pseudomonas Aeruginosa Infected Patients With Chronic Pulmonary Obstructive Disease, Non-cystic Fibrosis Bronchiectasis and Asthma? A Multicenter, Randomized, Controlled, Open-label Trial.PHASE4

TERMINATED · via Ciprofloxacin · NCT03262142

Clinical and Microbiologic Efficacy of Ciprofloxacin for the Treatment of Uncomplicated Urinary Tract Infection in Adult Women.PHASE4

COMPLETED · via Ciprofloxacin · NCT03366207

Cluster-randomized Trial to Evaluate the Impact of Ciprofloxacin for Contacts of Cases of Meningococcal Meningitis as an Epidemic ResponsePHASE4

COMPLETED · via Ciprofloxacin · NCT02724046

ClinicalTrials.gov via the drug-target graph.

What's happening now

12

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 2 drugs that target this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.

  1. Label change2026-07-22

    Label change: CIPROFLOXACIN (ANDA076558)

    fda · regulatory · fda · via Ciprofloxacin

  2. Label change2026-07-22

    Label change: CIPROFLOXACIN (ANDA076794)

    fda · regulatory · fda · via Ciprofloxacin

  3. New publication2023-09-12
    Global diversity and antimicrobial resistance of typhoid fever pathogens: Insights from a meta-analysis of 13,000 <i>Salmonella</i> Typhi genomes.

    eLife · 2023 · 93 citations · Europe PMC · via Ciprofloxacin

  4. Label change2023-08-31

    Label change: CIPROFLOXACIN (ANDA076558)

    fda · regulatory · fda · via Ciprofloxacin

  5. Label change2023-08-31

    Label change: CIPROFLOXACIN (ANDA076558)

    fda · regulatory · fda · via Ciprofloxacin

  6. Label change2023-08-31

    Label change: CIPROFLOXACIN (ANDA076558)

    fda · regulatory · fda · via Ciprofloxacin

  7. Label change2023-08-31

    Label change: CIPROFLOXACIN (ANDA076558)

    fda · regulatory · fda · via Ciprofloxacin

  8. Label change2023-08-31

    Label change: CIPROFLOXACIN (ANDA076558)

    fda · regulatory · fda · via Ciprofloxacin

  9. Safety communication2014-12-11

    Drug Safety Update: Norfloxacin: restricted use in urinary infections

    mhra · safety · mhra · via norfloxacin

  10. New publication2012-02-01
    Cefpodoxime vs ciprofloxacin for short-course treatment of acute uncomplicated cystitis: a randomized trial.

    JAMA · 2012 · 48 citations · Europe PMC · via Ciprofloxacin

  11. New publication2011-09-01
    Comparative efficacy and safety of 4 randomized regimens to treat early Pseudomonas aeruginosa infection in children with cystic fibrosis.

    Archives of pediatrics & adolescent medicine · 2011 · 162 citations · Europe PMC · via Ciprofloxacin

  12. New publication2008-11-01
    The pervasive effects of an antibiotic on the human gut microbiota, as revealed by deep 16S rRNA sequencing.

    PLoS biology · 2008 · 1,694 citations · Europe PMC · via Ciprofloxacin

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.