Structural analysis of the diadenylate cyclase reaction of DNA-integrity scanning protein A (DisA) and its inhibition by 3′-dATP

2015 ◽  
Vol 469 (3) ◽  
pp. 367-374 ◽  
Author(s):  
Martina Müller ◽  
Tobias Deimling ◽  
Karl-Peter Hopfner ◽  
Gregor Witte

Structures of Thermotoga maritima DNA-integrity-scanning protein A (DisA) in different reaction states describe the diadenylate cyclase (DAC) reaction and the possibility of its inhibition. We conclude that the mechanisms of cyclic-di-AMP (c-di-AMP) synthesis and its inhibition are conserved among different DAC enzymes and bacterial species.

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 82
Author(s):  
Liping Liu ◽  
Hanne Ingmer ◽  
Martin Vestergaard

Resveratrol has been extensively studied due to its potential health benefits in multiple diseases, for example, cancer, obesity and cardiovascular diseases. Besides these properties, resveratrol displays inhibitory activity against a wide range of bacterial species; however, the cellular effects of resveratrol in bacteria remain incompletely understood, especially in the human pathogen, Staphylococcus aureus. In this study, we aimed to identify intrinsic resistance genes that aid S. aureus in tolerating the activity of resveratrol. We screened the Nebraska Transposon Mutant Library, consisting of 1920 mutants with inactivation of non-essential genes in S. aureus JE2, for increased susceptibly to resveratrol. On agar plates containing 0.5× the minimum inhibitory concentration (MIC), 17 transposon mutants failed to grow. Of these, four mutants showed a two-fold reduction in MIC, being the clpP protease mutant and three mutants with deficiencies in the electron transport chain (menD, hemB, aroC). The remaining 13 mutants did not show a reduction in MIC, but were confirmed by spot-assays to have increased susceptibility to resveratrol. Several genes were associated with DNA damage repair (recJ, xerC and xseA). Treatment of S. aureus JE2 with sub-inhibitory concentrations of resveratrol did not affect the expression of recJ, xerC and xseA, but increased expression of the SOS–stress response genes lexA and recA, suggesting that resveratrol interferes with DNA integrity in S. aureus. Expression of error-prone DNA polymerases are part of the SOS–stress response and we could show that sub-inhibitory concentrations of resveratrol increased overall mutation frequency as measured by formation of rifampicin resistant mutants. Our data show that DNA repair systems are important determinants aiding S. aureus to overcome the inhibitory activity of resveratrol. Activation of the SOS response by resveratrol could potentially facilitate the development of resistance towards conventional antibiotics in S. aureus.


2013 ◽  
Vol 42 (5) ◽  
pp. 3478-3491 ◽  
Author(s):  
Wei Wang ◽  
Jingjin Ding ◽  
Ying Zhang ◽  
Yonglin Hu ◽  
Da-Cheng Wang

Abstract Natural transformation (NT) in bacteria is a complex process, including binding, uptake, transport and recombination of exogenous DNA into the chromosome, consequently generating genetic diversity and driving evolution. DNA processing protein A (DprA), which is distributed among virtually all bacterial species, is involved in binding to the internalized single-stranded DNA (ssDNA) and promoting the loading of RecA on ssDNA during NTs. Here we present the structures of DNA_processg_A (DprA) domain of the Helicobacter pylori DprA (HpDprA) and its complex with an ssDNA at 2.20 and 1.80 Å resolutions, respectively. The complex structure revealed for the first time how the conserved DprA domain binds to ssDNA. Based on structural comparisons and binding assays, a unique ssDNA-binding mode is proposed: the dimer of HpDprA binds to ssDNA through two small, positively charged binding pockets of the DprA domains with classical Rossmann folds and the key residue Arg52 is re-oriented to ‘open’ the pocket in order to accommodate one of the bases of ssDNA, thus enabling HpDprA to grasp substrate with high affinity. This mode is consistent with the oligomeric composition of the complex as shown by electrophoretic mobility-shift assays and static light scattering measurements, but differs from the direct polymeric complex of Streptococcus pneumoniae DprA–ssDNA.


1995 ◽  
Vol 270 (9) ◽  
pp. 4534-4543 ◽  
Author(s):  
Xavier V. Gomes ◽  
Marc S. Wold

2008 ◽  
Vol 57 (4) ◽  
pp. 367-376 ◽  
Author(s):  
Takeshi Kimura ◽  
Zenichiro Kato ◽  
Hidenori Ohnishi ◽  
Hidehito Tochio ◽  
Masahiro Shirakawa ◽  
...  

2000 ◽  
Vol 182 (24) ◽  
pp. 7078-7082 ◽  
Author(s):  
Kunitoshi Yamanaka ◽  
Jihwan Hwang ◽  
Masayori Inouye

ABSTRACT A gene encoding a putative GTP-binding protein, a TrmE homologue that is highly conserved in both prokaryotes and eukaryotes, was cloned from Thermotoga maritima, a hyperthermophilic bacterium.T. maritima TrmE was overexpressed in Escherichia coli and purified. TrmE has a GTPase activity but no ATPase activity. The GTPase activity can be competed with GTP, GDP, and dGTP but not with GMP, ATP, CTP, or UTP. Km andk cat at 70°C were 833 μM and 9.3 min−1, respectively. Our results indicate that TrmE is a GTP-binding protein with a very high intrinsic GTP hydrolysis rate. We also propose that TrmE homologues constitute a novel subfamily of the GTPase superfamily.


Biochemistry ◽  
2014 ◽  
Vol 53 (18) ◽  
pp. 3052-3061 ◽  
Author(s):  
Michael D. Feldkamp ◽  
Aaron C. Mason ◽  
Brandt F. Eichman ◽  
Walter J. Chazin

1998 ◽  
Vol 66 (8) ◽  
pp. 3656-3665 ◽  
Author(s):  
Run-Pan Du ◽  
Qijun Wang ◽  
Yan-Ping Yang ◽  
Anthony B. Schryvers ◽  
Pele Chong ◽  
...  

ABSTRACT The lactoferrin receptor genes from two strains of Moraxella catarrhalis have been cloned and sequenced. The lfrgenes are arranged as lbpB followed by lbpA, a gene arrangement found in lactoferrin and transferrin receptor operons from several bacterial species. In addition, a third open reading frame, orf3, is located one nucleotide downstream oflbpA. The deduced lactoferrin binding protein A (LbpA) sequences from the two strains were found to be 99% identical, the LbpB sequences were 92% identical, and the ORF3 proteins were 98% identical. The lbpB gene was PCR amplified and sequenced from a third strain of M. catarrhalis, and the encoded protein was found to be 77% identical and 84% similar to the other LbpB proteins. Recombinant LbpA and LbpB proteins were expressed fromEscherichia coli, and antisera raised to the purified proteins were used to assess antigenic conservation in a panel ofM. catarrhalis strains. The recombinant proteins were tested for the ability to bind human lactoferrin following gel electrophoresis and electroblotting, and rLbpB, but not rLbpA, was found to bind lactoferrin. Bactericidal antibody activity was measured, and while the anti-rLbpA antiserum was not bactericidal, the anti-rLbpB antisera were found to be weakly bactericidal. Thus, LbpB may have potential as a vaccine candidate.


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