Molecular cloning, sequence analysis and structure modeling of OmpR, the response regulator of Aeromonas hydrophila

Abstract

The ability of bacteria to survive and proliferate in changing environmental conditions, and during host cell invasion is the key to their pathogenicity. In order to achieve this, the bacteria use a signal transduction system, the two component regulatory system, which consists of a sensor kinase and a response regulator. The EnvZ/OmpR system regulates the porin genes ompF/ompC in response to changes in osmolarity. In the present study, the ompR gene of Aeromonas hydrophila (isolate Ah17) was cloned, sequenced and characterized. Further an attempt was made to analyze the structural characteristics of the OmpR protein from Aeromonas hydrophila. The three dimensional structure of the protein was predicted by homology modeling and the modeled structure was compared to other members of two component response regulators. This study would be helpful for structure based drug design approaches to generate drugs against this harmful pathogen to control its proliferation in both human and fish hosts.

Altered Outer Membrane Transcriptome Balance with AmpC Overexpression in Carbapenem-Resistant Enterobacter cloacae

“…Among possible mechanisms involved in decreasing OM permeability due to OmpC-directed OM porin balance, we can mention the increased expression of bolA morphogene responsible for adaptive stress response in Enterobacteriaceae (Freire et al, 2006), and the TolC, LamB, and Dps proteins which can significantly influence OM protein network (Yang et al, 2011). Handling of the OM protein balance according to environmental factors may also be conditioned by the two-component regulatory system OmpR-EnvZ (Chhabra et al, 2012; Shimada et al, 2015). Another mechanism influencing the relationship between produced OM proteins is a two-component system CpxA-CpxR closely associated with the activity of the AtpB protein, the β-subunit of ATP synthase localized in the plasma membrane (Lin et al, 2012).…”

Heterologous Soluble Expression of Recombinant OmpR of <i>Aeromonas hydrophila</i> and Its Immunogenic Potential

“…Role of OmpR and OmpR-dependent genes in bacterial virulence has been elucidated in a number of bacterial species and hence the proteins of this system become a potential drug target or vaccine candidates. We have earlier reported cloning and characterization of the OmpR gene of A. hydrophila [28] and in silico homology modelling of the OmpR of A. hydrophila for structure based drug design. However, for a protein to be evaluated as a vaccine candidate or drug target, large amounts of purified proteins are required.…”

“…The ompR gene of Ah17 along with upstream and downstream region was cloned in PBCKS+ cloning vector [28]. The full length gene encoding mature OmpR of A. hydrophila Ah17 was PCR amplified using pAhOmpR (EMBL acc no.…”

“…The full length gene encoding mature OmpR of A. hydrophila Ah17 was PCR amplified using pAhOmpR (EMBL acc no. AM084417.1) (Locus CAJ29527.1) [28] as the template and gene specific primers (Forward: 5'-CCGCTCGAGATGCGGATCCTGTTGGTGG-3'; Reverse: 5'-ACCGGTACCTCATGCCCGGCCGTCCCGG CGC-3') containing XhoI and KpnI (in bold letters) in forward and reverse primers, respectively.…”

“…Since the OmpR gene reported earlier contained 5'-and 3'-flanking sequences, including the signal sequence [28], cloning of the gene region encoding the mature OmpR in expression vector was carried out. PCR amplification of the OmpR encoding the mature OmpR resulted in amplification of ~0.7 kb DNA fragment of the expected size.…”