Possible involvement of put A gene in Helicobacter pylori colonization in the stomach and motility

Nakajima, Kazuhiko; Inatsu, Sakiko; Mizote, Tomoko; Nagata, Yoko; Aoyama, Kazue; Fukuda, Yoshihiro; Nagata, Kumiko

doi:10.2220/biomedres.29.9

Cited by 35 publications

(44 citation statements)

References 36 publications

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“…In S. meliloti, a DputA strain has a weakened ability to form root colonies [35] and, moreover, strains complemented with additional copies of putA are more competitive at establishing a symbiotic relationship with alfalfa [36,37]. The Put system has also been linked to infectivity in both Helicobacter hepaticas and Helicobacter pylori [28,29,38], and the Put system plays a role in regulating the cell cycle within Ehrlichia chaffeensis [39]. Our data demonstrate that PutA and PutR are also required for B. abortus to infect animals ( Fig.…”

Section: Discussionmentioning

confidence: 99%

Proline utilization system is required for infection by the pathogenic α-proteobacterium Brucella abortus

et al. 2017

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Proline utilization (Put) systems have been described in a number of bacteria; however, the importance and functionality of the Put system in the intracellular pathogen Brucellaabortus has not been explored. Generally, bacterial Put systems are composed of the bifunctional enzyme proline dehydrogenase PutA and its transcriptional activator PutR. Here, we demonstrate that the genes putA (bab2_0518) and putR (bab2_0517) are critical for the chronic infection of mice by B. abortus, but putA and putR are not required for the survival and replication of the bacteria in naive macrophages. Additionally, in vitro experiments revealed that putR is necessary for the ability of the bacteria to withstand oxidative stress, as a DputR deletion strain is hypersensitive to hydrogen peroxide exposure. Quantitative reverse transcription-PCR and putA-lacZ transcriptional reporter studies revealed that PutR acts as a transcriptional activator of putA in Brucella, and electrophoretic mobility shift assays confirmed that PutR binds directly to the putA promoter region. Biochemical analyses demonstrated that a purified recombinant B. abortus PutA protein possesses quintessential proline dehydrogenase activity, as PutA is capable of catalysing the conversion of proline to glutamate. Altogether, these data are the first to reveal that the Put system plays a significant role in the ability of B. abortus to replicate and survive within its host, as well as to describe the genetic regulation and biochemical activity of the Put system in Brucella.

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Section: Discussionmentioning

confidence: 99%

Proline utilization system is required for infection by the pathogenic α-proteobacterium Brucella abortus

et al. 2017

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“…Channeling in PutA may be particularly beneficial for bacteria that have adapted to use proline as a fuel source. One example is H. pylori, which utilizes proline as a preferred energy source in the gut environment, where proline levels in the gastric juice of infected patients are 10-fold higher compared to uninfected individuals (4,38). Also, channeling segregates the P5C produced by proline catabolism from the proline biosynthetic pathway, which also uses P5C as an intermediate.…”

Section: Discussionmentioning

confidence: 99%

Crystal structure of the bifunctional proline utilization A flavoenzyme from Bradyrhizobium japonicum

Srivastava

Schuermann

White

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

130

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The bifunctional proline catabolic flavoenzyme, proline utilization A (PutA), catalyzes the oxidation of proline to glutamate via the sequential activities of FAD-dependent proline dehydrogenase (PRODH) and NAD þ -dependent Δ 1 -pyrroline-5-carboxylate dehydrogenase (P5CDH) domains. Although structures for some of the domains of PutA are known, a structure for the full-length protein has not previously been solved. Here we report the 2.1 Å resolution crystal structure of PutA from Bradyrhizobium japonicum, along with data from small-angle x-ray scattering, analytical ultracentrifugation, and steady-state and rapid-reaction kinetics. PutA forms a ring-shaped tetramer in solution having a diameter of 150 Å. Within each protomer, the PRODH and P5CDH active sites face each other at a distance of 41 Å and are connected by a large, irregularly shaped cavity. Kinetics measurements show that glutamate production occurs without a lag phase, suggesting that the intermediate, Δ 1 -pyrroline-5-carboxylate, is preferably transferred to the P5CDH domain rather than released into the bulk medium. The structural and kinetic data imply that the cavity serves both as a microscopic vessel for the hydrolysis of Δ 1 -pyrroline-5-carboxylate to glutamate semialdehyde and a protected conduit for the transport of glutamate semialdehyde to the P5CDH active site.proline catabolism | substrate channeling

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“…Furthermore, through comparative analyses among several S. enterica serovars, it has been suggested that a relationship between swarming and intestinal colonization must exist in this bacterial species (32). Likewise, swarming is known to be important for the virulence of other bacterial pathogens, such as Proteus mirabilis, Helicobacter pylori, Vibrio parahaemolyticus, and Campylobacter jejuni (43,44,51,57). In addition, it has been reported that the RecA protein is necessary for the swarming motility of E. coli, since recA mutants of this species do not swarm (28).…”

Section: S Enterica Recao6869 Mutants Do Not Swarmmentioning

confidence: 99%

Overexpression of therecAGene Decreases Oral but Not Intraperitoneal Fitness ofSalmonella enterica

et al. 2010

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Transcription of the Salmonella enterica recA gene is negatively controlled by the LexA protein, the repressor of the SOS response. The introduction of a mutation (recAo6869) in the LexA binding site, in the promoter region of the S. enterica ATCC 14028 recA gene, allowed the analysis of the effect that RecA protein overproduction has on the fitness of this virulent strain. The fitness of orally but not intraperitoneally inoculated recAo6869 cells decreased dramatically. However, the SOS response of this mutant was induced normally, and there was no increase in the sensitivity of the strain toward DNA-damaging agents, bile salts, or alterations in pH. Nevertheless, S. enterica recAo6869 cells were unable to swarm and their capacity to cross the intestinal epithelium was significantly reduced. The swarming deficiency in recAo6869 cells is independent of the flagellar phase. Moreover, swimming activity of the recAo6869 strain was not diminished with respect to the wild type, indicating that the flagellar synthesis is not affected by RecA protein overproduction. In contrast, swarming was recovered in a recAo6869 derivative that overproduced CheW, a protein known to be essential for this function. These data demonstrate that an equilibrium between the intracellular concentrations of RecA and CheW is necessary for swarming in S. enterica. Our results are the first to point out that the SOS response plays a critical role in the prevention of DNA damage by abolishing bacterial swarming in the presence of a genotoxic compound.In bacteria, RecA is a key protein in homologous recombination, enabling the alignment of DNA molecules prior to strand exchange (17). RecA is also the positive regulator of the SOS response, one of the most-well-studied DNA repair systems in bacteria (54). In Escherichia coli and other Enterobacteriaceae, the cellular SOS network consists of more than 40 genes whose products act together to ensure cell survival after DNA damage (25). The negative regulator of the SOS system, LexA, binds to a specific sequence, the SOS box, which is located in the promoter region of the controlled genes (54). In Gammaproteobacteria, the SOS box is an imperfect palindrome, comprising the sequence CTGTN 8 ACAG (54) and varying among the different bacterial phyla (22).The induction pathway of the SOS response seems to be conserved in all bacteria in which this DNA repair system is found. The RecA protein is activated after binding to singlestranded DNA resulting from inhibition of chromosomal replication (48). In turn, the activated RecA triggers autocatalytic cleavage of the LexA repressor. In E. coli, this cleavage occurs in the Ala 84 -Gly 85 bond of the regulator (36) in a process mediated by the residues Ser 119 and Lys 156 . Autocleavage resembles that described for serine proteases (38), and it prevents the binding of LexA to its specific recognition motif in the promoter region of SOS genes.In addition to DNA repair genes, the SOS response involves lytic-cycle repressors of temperate bacteriophages (54). In so...

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Possible involvement of put A gene in Helicobacter pylori colonization in the stomach and motility

Cited by 35 publications

References 36 publications

Proline utilization system is required for infection by the pathogenic α-proteobacterium Brucella abortus

Proline utilization system is required for infection by the pathogenic α-proteobacterium Brucella abortus

Crystal structure of the bifunctional proline utilization A flavoenzyme from Bradyrhizobium japonicum

Overexpression of therecAGene Decreases Oral but Not Intraperitoneal Fitness ofSalmonella enterica

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