Functional Escherichia coli 30S ribosomal subunits can be reconstituted in vitro. However, slow kinetics and sharp temperature dependence suggest additional assembly factors are present in vivo. Extract activation of in vitro assembly results in association of DnaK/hsp70 chaperone components with pre-30S particles. Purified DnaK, its cochaperones DnaJ and GrpE, and ATP can facilitate reconstitution of functional 30S subunits under otherwise nonpermissive conditions. A link has been observed between DnaK, 30S subunit components, and ribosome biogenesis in vivo as well as in vitro. These studies reveal a novel role for the DnaK/hsp70 chaperone system, in addition to its well-documented role in protein folding, and suggest that 30S subunit assembly can be facilitated.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s1097-2765(02)00562-2 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
In silico analysis of non-conventional gene targets for genetic interventions to enhance fatty acid production: a review.
Mol Biol Rep
January 2025
Department of Biological Sciences, Sunandan Divatia School of Science, NMIMS Deemed to be University, Vile Parle (West), Mumbai, 400056, India.
Since the 1990s, fatty acids (FA) have drawn significant industrial attention due to their diverse applications creating a demand for biological systems capable of producing high FA titers. While various strategies have been explored to achieve this, many of the conventional approaches rely on extensive genetic manipulations, which often result in strain instability, thus limiting its potential to yield better FA titers. Moreover, stresses such as pH, osmotic, and oxidative imbalances generated during FA production aggravate these challenges, further limiting FA titers.
View Article and Find Full Text PDFEvolutionary Pro-To-Thr Mutation in the Intrinsically Disordered Domain of ANP32 Family Members Modulates Their Target Binding Modes.
Adv Sci (Weinh)
January 2025
Institute for Chemical Research (IIQ), Scientific Research Center "Isla de la Cartuja" (cicCartuja), University of Seville-CSIC, Avda. Americo Vespucio 49, Seville, 41092, Spain.
Gene duplication has allowed protein evolution toward novel functions and mechanisms. The differences between paralogous genes frequently rely on the sequence of disordered regions. For instance, in mammals, the chaperones ANP32A and ANP32B share a common evolutionary line and have some exchangeable functions based on their similar N-terminal domains.
View Article and Find Full Text PDFAssociation of serum and local GRP78 and CHOP expressions with disease progression in patients with non-traumatic osteonecrosis of femoral head.
J Orthop Surg Res
January 2025
Linyi People's Hospital postgraduate training base of Guangzhou University of Traditional Chinese Medicine, Linyi, Shandong, 276000, China.
Background: The endoplasmic reticulum stress (ER stress) has been involved in various musculoskeletal disorders including non-traumatic osteonecrosis of femoral head (NT-ONFH).
Objective: The current study aimed to investigate the association of glucose-regulated protein 78 (GRP78) as well as CCAAT/enhancer-binding protein homologous protein (CHOP) expressions in serum and femoral head (FH) tissues with NT-ONFH's severity.
Methods: We enrolled NT-ONFH patients (n = 150) alongside healthy controls (HCs, n = 150).
A conserved chaperone protein is required for the formation of a non-canonical type VI secretion system spike tip complex.
J Biol Chem
January 2025
Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1; Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada L8S 4K1. Electronic address:
Type VI secretion systems (T6SS) are dynamic protein nanomachines found in Gram-negative bacteria that deliver toxic effector proteins into target cells in a contact-dependent manner. Prior to secretion, many T6SS effector proteins require chaperones and/or accessory proteins for proper loading onto the structural components of the T6SS apparatus. However, despite their established importance, the precise molecular function of several T6SS accessory protein families remains unclear.
View Article and Find Full Text PDFHsp90, DnaK, and ClpB collaborate in protein reactivation.
Proc Natl Acad Sci U S A
February 2025
Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892.
Hsp70, Hsp90, and ClpB/Hsp100 are molecular chaperones that help regulate proteostasis. Bacterial and yeast Hsp70s and their cochaperones function synergistically with Hsp90s to reactivate inactive and aggregated proteins by a mechanism that requires a direct interaction between Hsp90 and Hsp70 both in vitro and in vivo. and yeast Hsp70s also collaborate in bichaperone systems with ClpB and Hsp104, respectively, to disaggregate and reactivate aggregated proteins and amyloids such as prions.
View Article and Find Full Text PDFWant 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!