ATP/GTP Hydrolysis Is Required for Oxazole and Thiazole Biosynthesis in the Peptide Antibiotic Microcin B17†

Biochemistry ◽  
1998 ◽  
Vol 37 (38) ◽  
pp. 13250-13261 ◽  
Author(s):  
Jill C. Milne ◽  
Andrew C. Eliot ◽  
Neil L. Kelleher ◽  
Christopher T. Walsh
Keyword(s):  
Peptide Antibiotic ◽  
Gtp Hydrolysis ◽  
Microcin B17

scholarly journals The Highly Conserved TldD and TldE Proteins of Escherichia coli Are Involved in Microcin B17 Processing and in CcdA Degradation

2002 ◽  
Vol 184 (12) ◽  
pp. 3224-3231 ◽  
Author(s):  
Noureddine Allali ◽  
Hassan Afif ◽  
Martine Couturier ◽  
Laurence Van Melderen
Keyword(s):  
Escherichia Coli ◽  
Topoisomerase Ii ◽  
Resistance Mechanism ◽  
Physiological Role ◽  
Leader Peptide ◽  
Peptide Antibiotic ◽  
Amino Terminal ◽  
Bacterial Mutants ◽  
Microcin B17

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.

Uptake and Mode of Action of the Peptide Antibiotic Microcin B17

1992 ◽  
pp. 15-17
Author(s):  
C. Hernández-Chico ◽  
O. Mayo ◽  
J. L. Vizán ◽  
M. Laviña ◽  
F. Moreno
Keyword(s):  
Mode Of Action ◽  
Peptide Antibiotic ◽  
Microcin B17

scholarly journals The peptide antibiotic microcin B17 induces double-strand cleavage of DNA mediated by E. coli DNA gyrase.

1991 ◽  
Vol 10 (2) ◽  
pp. 467-476 ◽  
Author(s):  
J. L. Vizán ◽  
C. Hernández-Chico ◽  
I. del Castillo ◽  
F. Moreno
Keyword(s):  
Dna Gyrase ◽  
Peptide Antibiotic ◽  
E Coli ◽  
Microcin B17

scholarly journals When an ATPase Is Not an ATPase: at Low Temperatures the C-Terminal Domain of the ABC Transporter CvaB Is a GTPase

1998 ◽  
Vol 180 (6) ◽  
pp. 1347-1353 ◽  
Author(s):  
Xiaotian Zhong ◽  
Phang C. Tai
Keyword(s):  
Low Temperatures ◽  
Nucleotide Binding ◽  
Binding Domain ◽  
Cross Linking ◽  
Peptide Antibiotic ◽  
Nucleotide Binding Domain ◽  
Gtp Hydrolysis ◽  
The Cross ◽  
Colicin V ◽  
Hydrolysis Activity

ABSTRACT The ATP-binding cassette (ABC) transporters belong to a large superfamily of proteins which share a common function and a common nucleotide-binding domain. The CvaB protein from Escherichia coli is a member of the bacterial ABC exporter subfamily and is essential for the export of the peptide antibiotic colicin V. Here we report that, surprisingly, the CvaB carboxyl-terminal nucleotide-binding domain (BCTD) can be preferentially cross-linked to GTP but not to ATP at low temperatures. The cross-linking is Mg2+ and Mn2+ dependent. However, BCTD possesses similar GTPase and ATPase activities at 37°C, with the same kinetic parameters and with similar responses to inhibitors. Moreover, a point mutation (D654H) in CvaB that completely abolishes colicin V secretion severely impairs both GTPase and ATPase activities in the corresponding BCTD, indicating that the two activities are from the same enzyme. Interestingly, hydrolysis activity of ATP is much more cold sensitive than that of GTP: BCTD possesses mainly GTP hydrolysis activity at 10°C, consistent with the cross-linking results. These findings suggest a novel mechanism for an ABC protein-mediated transport with specificity for GTP hydrolysis.

Isolation and structure elucidation of the 43-peptide antibiotic microcin B17

Peptides 1992 ◽  
1993 ◽  
pp. 117-118 ◽  
Author(s):  
A. Bayer ◽  
S. Stevanovic ◽  
S. Freund ◽  
J. W. Metzger ◽  
G. Jung
Keyword(s):  
Structure Elucidation ◽  
Peptide Antibiotic ◽  
Microcin B17

scholarly journals Construction and Characterization of Mutations at Codon 751 of the Escherichia coli gyrB Gene That Confer Resistance to the Antimicrobial Peptide Microcin B17 and Alter the Activity of DNA Gyrase

2001 ◽  
Vol 183 (6) ◽  
pp. 2137-2140 ◽  
Author(s):  
Francisco J. del Castillo ◽  
Ignacio del Castillo ◽  
Felipe Moreno
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Dna Gyrase ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Peptide Antibiotic ◽  
Resistant Mutants ◽  
Different Levels ◽  
Microcin B17

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.

Analysis of the Mechanism of Microtubule Dynamic Instability Using a UV Microbeam to Sever Elongating Microtubules

1988 ◽  
Vol 46 ◽  
pp. 122-123
Author(s):  
R.A Walker ◽  
S. Inoue ◽  
E.D. Salmon
Keyword(s):  
Dynamic Instability ◽  
Microtubule Dynamic ◽  
Gtp Hydrolysis ◽  
Abrupt Transition ◽  
Microtubule Associated Proteins ◽  
Asymmetrical Structure ◽  
Associated Proteins

Microtubules polymerized in vitro from tubulin purified free of microtubule-associated proteins exhibit dynamic instability (1,2,3). Free microtubule ends exist in persistent phases of elongation or rapid shortening with infrequent, but, abrupt transitions between these phases. The abrupt transition from elongation to rapid shortening is termed catastrophe and the abrupt transition from rapid shortening to elongation is termed rescue. A microtubule is an asymmetrical structure. The plus end grows faster than the minus end. The frequency of catastrophe of the plus end is somewhat greater than the minus end, while the frequency of rescue of the plus end in much lower than for the minus end (4).The mechanism of catastrophe is controversial, but for both the plus and minus microtubule ends, catastrophe is thought to be dependent on GTP hydrolysis. Microtubule elongation occurs by the association of tubulin-GTP subunits to the growing end. Sometime after incorporation into an elongating microtubule end, the GTP is hydrolyzed to GDP, yielding a core of tubulin-GDP capped by tubulin-GTP (“GTP-cap”).

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