Streptolydigin

Streptolydigin (Portamycin) is a 3-acetyltetramic acid antibiotic and a potent bacterial RNA polymerase inhibitor with a Ki of 18 μM and a Kd of 15 μM. Streptolydigin inhibits RNA synthesis by binding to RNA polymerase and does not inhibit eukaryotic RNA polymerases[1][2][3]. Streptolydigin possess potent antibacterial activity, particularly against anaerobes and some Gram-positive aerobes[4].

Research Areas >> Infection

Signaling Pathways >> Cell Cycle/DNA Damage >> DNA/RNA Synthesis

Signaling Pathways >> Anti-infection >> Bacterial

Ki: 18 μM (Bacterial RNA polymerase)[3] Kd: 15 μM (Bacterial RNA polymerase)[3]

The antibiotic Streptolydigin (Stl) is a derivative of 3-acetyltetramic acid. Binding of Streptolydigin to RNA polymerase strictly depends on a noncatalytic magnesium ion which is likely chelated by the aspartate of the bridge helix of the active center[1]. Streptolydigin inhibits T. thermophilus RNA polymerase with a Ki of 1.8 μM[3]. Streptolydigin (Stl) inhibits initiation, elongation, and pyrophosphorolysis by bacterial RNA polymerase. Streptolydigin interacts with three structural elements within RNAP: the Stl pocket, the bridge helix, and the trigger-loop region. The Streptolydigin streptolol moiety interacts with the Streptolydigin pocket and bridge helix, and the Streptolydigin tetramic-acid moiety interacts with the trigger-loop region[3].

[1]. Zorov S, et al. Antibiotic streptolydigin requires noncatalytic Mg2+ for binding to RNA polymerase. Antimicrob Agents Chemother. 2014;58(3):1420-4.

[2]. Temiakov D, et al. Structural basis of transcription inhibition by antibiotic streptolydigin. Mol Cell. 2005 Sep 2;19(5):655-66.

[3]. Tuske S, et al. Inhibition of bacterial RNA polymerase by streptolydigin: stabilization of a straight-bridge-helix active-center conformation. Cell. 2005 Aug 26;122(4):541-52.

[4]. Rosen T, et al. Aromatic dienoyl tetramic acids. Novel antibacterial agents with activity against anaerobes and staphylococci. J Med Chem. 1989 May;32(5):1062-9.

MOLECULAR FORMULA :

C32-H44-N2-O9

MOLECULAR WEIGHT :

600.78

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

533 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LDLo - Lowest published lethal dose

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Bird - chicken

DOSE/DURATION :

10 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

MUTATION DATA

TYPE OF TEST :

Mutation test systems - not otherwise specified

TEST SYSTEM :

Bacteria - Bacillus subtilis

DOSE/DURATION :

288 mg/L

REFERENCE :

FOMIAZ Folia Microbiologica (Prague). (Academia, Vodickova 40, 112 29 Prague 1, Czechoslavakia) V.4- 1959- Volume(issue)/page/year: 22,329,1977