Molecular characterization and regulatory analysis of dnaK operon of halophilic lactic acid bacterium Tetragenococcus halophila.

J Biosci Bioeng

Laboratory of Microbial Technology, Division of Microbial Science and Technology, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.

Published: November 2005

We have cloned and characterized the dnaK operon of Tetragenococcus halophila JCM5888. Nucleotide sequence analysis of cloned fragments showed that the dnaK operon consists of four open reading frames with the organization hrcA-grpE-dnaK-dnaJ. Two regulatory CIRCE (Controlling Inverted Repeat of Chaperone Expression) elements were identified in the region up-stream of hrcA. The T. halophila dnaK encoded a protein of 618 amino acids with a calculated molecular mass of 67 kDa. The deduced amino acid sequence of T. halophila DnaK showed high similarities with those of the corresponding DnaK homologues of Lactococcus lactis, Lactobacillus sakei and Bacillus subtilis. Using a pET expression system, the T. halophila DnaK was overexpressed in Escherichia coli and the purified DnaK was found to exhibit ATPase and refolding activities. Northern hybridization analysis revealed that the transcription of the dnaK gene was induced by heat shock, and several transcripts were detected including a tetra-cistronic mRNA with a maximum size of 4.9-kb which corresponds to the transcript of the complete dnaK operon. The amount of dnaK transcripts increased about 3.5-fold at high NaCl concentration of 3-4 M, but not at the same KCl concentrations. These results suggest that the cloned DnaK acts as a functional molecular chaperone and plays an important role in salinity adaptation.

Download full-text PDF

Source

Publication Analysis

Top Keywords

dnak operon
16
dnak
12
halophila dnak
12
tetragenococcus halophila
8
halophila
5
molecular characterization
4
characterization regulatory
4
regulatory analysis
4
analysis dnak
4
operon
4

Similar Publications

Decoding wheat contamination through self-assembled whole-cell biosensor combined with linear and non-linear machine learning algorithms.

Biosens Bioelectron

January 2025

Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing, 100093, PR China. Electronic address:

The contamination of mycotoxins is a serious problem around the world. It has detrimental effects on human beings and leads to tremendous economic loss. It is essential to develop a rapid and non-destructive method for contamination recognition particularly for early alarm.

View Article and Find Full Text PDF

Skin serves as both barrier and interface between body and environment. Skin microbes are intermediaries evolved to respond, transduce, or act in response to changing environmental or physiological conditions. We quantified genome-wide changes in gene expression levels for one abundant skin commensal, , in response to an internal physiological signal, glucose levels, and an external environmental signal, temperature.

View Article and Find Full Text PDF

sp. strain SVR uses antimonate [Sb(V)] as a terminal electron acceptor for anaerobic respiration. Here, we visualized a possible key enzyme, periplasmic Sb(V) reductase (Anr), via active staining and non-denaturing gel electrophoresis.

View Article and Find Full Text PDF

Lambdoid bacteriophages are excellent models in studies on molecular aspects of virus-host interactions. However, some of them carry genes encoding toxins which are responsible for virulence of pathogenic strains of bacteria. Shiga toxin-converting bacteriophages (Stx phages) encode Shiga toxins that cause virulence of enterohemorrhagic Escherichia coli (EHEC), and their effective production depends on Stx prophage induction.

View Article and Find Full Text PDF

The research aimed to establish a multidrug-resistant Klebsiella pneumoniae-induced genetic model for mastitis considering the alternative mechanisms of the DjlA-mediated CbpA protein regulation. The Whole Genome Sequencing of the newly isolated K. pneumoniae strain was conducted to annotate the frequently occurring antibiotic resistance and virulence factors following PCR and MALDI-TOF mass-spectrophotometry.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!