Synthesis of the DNA Gyrase Inhibitor Microcin B17, a 43-Peptide Antibiotic with Eight Aromatic Heterocycles in its Backbone

1996 ◽  
Vol 35 (1314) ◽  
pp. 1506-1508 ◽  
Author(s):  
Georgi Videnov ◽  
Dietmar Kaiser ◽  
Marc Brooks ◽  
Günther Jung
1991 ◽  
Vol 10 (2) ◽  
pp. 467-476 ◽  
Author(s):  
J. L. Vizán ◽  
C. Hernández-Chico ◽  
I. del Castillo ◽  
F. Moreno

2001 ◽  
Vol 183 (6) ◽  
pp. 2137-2140 ◽  
Author(s):  
Francisco J. del Castillo ◽  
Ignacio del Castillo ◽  
Felipe Moreno

ABSTRACT Microcin B17 is a peptide antibiotic that inhibits DNA replication in Escherichia coli by targeting DNA gyrase. Previously, two independently isolated microcin B17-resistant mutants were shown to harbor the same gyrB point mutation that results in the replacement of tryptophan 751 by arginine in the GyrB polypeptide. We used site-directed mutagenesis to construct mutants in which tryptophan 751 was deleted or replaced by other amino acids. These mutants exhibit altered DNA gyrase activity and different levels of resistance to microcin B17.


2001 ◽  
Vol 98 (14) ◽  
pp. 7712-7717 ◽  
Author(s):  
D. B. Zamble ◽  
D. A. Miller ◽  
J. G. Heddle ◽  
A. Maxwell ◽  
C. T. Walsh ◽  
...  

2019 ◽  
Vol 73 (4) ◽  
pp. 749-762.e5 ◽  
Author(s):  
Dmitry Ghilarov ◽  
Clare E.M. Stevenson ◽  
Dmitrii Y. Travin ◽  
Julia Piskunova ◽  
Marina Serebryakova ◽  
...  

2002 ◽  
Vol 184 (12) ◽  
pp. 3224-3231 ◽  
Author(s):  
Noureddine Allali ◽  
Hassan Afif ◽  
Martine Couturier ◽  
Laurence Van Melderen

ABSTRACT Microcin B17 (MccB17) is a peptide antibiotic produced by Escherichia coli strains carrying the pMccB17 plasmid. MccB17 is synthesized as a precursor containing an amino-terminal leader peptide that is cleaved during maturation. Maturation requires the product of the chromosomal tldE (pmbA) gene. Mature microcin is exported across the cytoplasmic membrane by a dedicated ABC transporter. In sensitive cells, MccB17 targets the essential topoisomerase II DNA gyrase. Independently, tldE as well as tldD mutants were isolated as being resistant to CcdB, another natural poison of gyrase encoded by the ccd poison-antidote system of plasmid F. This led to the idea that TldD and TldE could regulate gyrase function. We present in vivo evidence supporting the hypothesis that TldD and TldE have proteolytic activity. We show that in bacterial mutants devoid of either TldD or TldE activity, the MccB17 precursor accumulates and is not exported. Similarly, in the ccd system, we found that TldD and TldE are involved in CcdA and CcdA41 antidote degradation rather than being involved in the CcdB resistance mechanism. Interestingly, sequence database comparisons revealed that these two proteins have homologues in eubacteria and archaebacteria, suggesting a broader physiological role.


1994 ◽  
Vol 91 (10) ◽  
pp. 4519-4523 ◽  
Author(s):  
P. Yorgey ◽  
J. Lee ◽  
J. Kordel ◽  
E. Vivas ◽  
P. Warner ◽  
...  

Biochemistry ◽  
1998 ◽  
Vol 37 (38) ◽  
pp. 13250-13261 ◽  
Author(s):  
Jill C. Milne ◽  
Andrew C. Eliot ◽  
Neil L. Kelleher ◽  
Christopher T. Walsh

2015 ◽  
Vol 59 (11) ◽  
pp. 6689-6695 ◽  
Author(s):  
George A. Jacoby ◽  
Marian A. Corcoran ◽  
David C. Hooper

ABSTRACTQnr is a plasmid-encoded and chromosomally determined protein that protects DNA gyrase and topoisomerase IV from inhibition by quinolones. Despite its prevalence worldwide and existence prior to the discovery of quinolones, its native function is not known. Other synthetic compounds and natural products also target bacterial topoisomerases. A number were studied as molecular probes to gain insight into how Qnr acts. Qnr blocked inhibition by synthetic compounds with somewhat quinolone-like structure that target the GyrA subunit, such as the 2-pyridone ABT-719, the quinazoline-2,4-dione PD 0305970, and the spiropyrimidinetrione pyrazinyl-alkynyl-tetrahydroquinoline (PAT), indicating that Qnr is not strictly quinolone specific, but Qnr did not protect against GyrA-targeting simocyclinone D8 despite evidence that both simocyclinone D8 and Qnr affect DNA binding to gyrase. Qnr did not affect the activity of tricyclic pyrimidoindole or pyrazolopyridones, synthetic inhibitors of the GyrB subunit, or nonsynthetic GyrB inhibitors, such as coumermycin A1, novobiocin, gyramide A, or microcin B17.Thus, in this set of compounds the protective activity of Qnr was confined to those that, like quinolones, trap gyrase on DNA in cleaved complexes.


Author(s):  
C. Hernández-Chico ◽  
O. Mayo ◽  
J. L. Vizán ◽  
M. Laviña ◽  
F. Moreno

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