Abstract
ClpB, an ATP-dependent molecular chaperone, is involved in metabolic pathways and plays important roles in microorganisms under stress conditions. Metabolic pathways and stress resistance are important characteristics of industrially -relevant bacteria during fermentation. Nevertheless, ClpB-related observations have been rarely reported in industrially -relevant microorganisms. Herein, we found a homolog of ClpB from Corynebacterium crenatum. The amino acid sequence of ClpB was analyzed, and the recombinant ClpB protein was purified and characterized. The full function of ClpB requires DnaK as chaperone protein. For this reason, dnaK/clpB deletion mutants and the complemented strains were constructed to investigate the role of ClpB. The results showed that DnaK/ClpB is not essential for the survival of C. crenatum MT under pH and alcohol stresses. The ClpB-deficient or DnaK-deficient C. crenatum mutants showed weakened growth during thermal stress. In addition, the results demonstrated that deletion of the clpB gene affected glucose consumption and L-arginine, L-glutamate, and lactate production during fermentation.
Highlights
Molecular chaperones are essential for homeostasis in living cells
The middle region within the first AAA cassette contains a bundle of four helices approximately 120 amino acids long, which is required for ClpB interactions with DnaK and mediates allosteric functions during disaggregation and hydrolysis (Haslberger et al, 2007)
The two sequence alignments indicated that the protein sequences of ClpB between C. crenatum MT and E. coli are highly conserved in the two ATP hydrolysis domains (Figure 1C), in which all 15 amino acid residues forming hydrogen bonds are conserved
Summary
Molecular chaperones are essential for homeostasis in living cells. Their fundamental role is to aid proteins in achieving their functional and final conformations (Hartl and Hayer-Hartl, 2002). ClpB is an ATP-dependent molecular chaperone that reactivates and disaggregates aggregated proteins with the DnaK chaperone system (Mogk et al, 2018). Similar to other ATP-dependent molecular chaperones, ClpB forms a hexameric ring structure to mediate protein disaggregation. The mechanism of the ClpB-catalyzed protein disaggregation is the coupling of ATP hydrolysis with the translocation of polypeptide substrates through the central channel of barrel-shaped hexamers (Li et al, 2015). Multiple enzymes of the central carbon metabolism are potential substrates of ClpB. This protein has regulatory activity in terms of the metabolism. The majority of ClpB-interacting proteins in Leptospira interrogans is associated with metabolic pathways, such as the tricarboxylic
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
