Biomaterial Database

GroEL and GroES control of substrate flux in the in vivo folding pathway of phage P22 coat protein. 1998

W S Nakonechny, and C M Teschke

Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269-3125, USA.

Our present understanding of the action of the chaperonins GroEL/S on protein folding is based primarily on in vitro studies, whereas the folding of proteins in the cellular milieu has not been as thoroughly investigated. We have developed a means of examining in vivo protein folding and assembly that utilizes the coat protein of bacteriophage P22, a naturally occurring substrate of GroEL/S. Here we show that amino acid substitutions in coat protein that cause a temperature-sensitive-folding (tsf) phenotype slowed assembly rates upon increasing the temperature of cell growth. Raising cellular concentrations of GroEL/S increased the rate of assembly of the tsf mutant coat proteins to nearly that of wild-type (WT) coat protein by protecting a thermolabile folding intermediate from aggregation, thereby increasing the concentration of assembly-competent coat protein. The rate of release of the tsf coat proteins from the GroEL/S-coat protein ternary complex was approximately 2-fold slower at non-permissive temperatures when compared with the release of WT coat protein. However, the rate of release of WT or tsf coat proteins at each temperature remained constant regardless of GroEL/S levels. Thus, raising the cellular concentration of GroEL/S increased the amount of assembly-competent tsf coat proteins not by altering the rates of folding but by increasing the probability of GroEL/S-coat protein complex formation.

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D002213	Capsid	The outer protein protective shell of a virus, which protects the viral nucleic acid. Capsids are composed of repeating units (capsomers or capsomeres) of CAPSID PROTEINS which when assembled together form either an icosahedral or helical shape.	Procapsid,Prohead,Capsids,Procapsids,Proheads
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D012486	Salmonella typhimurium	A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.	Salmonella typhimurium LT2
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D017100	Bacteriophage P22	A species of temperate bacteriophage in the genus P22-like viruses, family PODOVIRIDAE, that infects SALMONELLA species. The genome consists of double-stranded DNA, terminally redundant, and circularly permuted.	Enterobacteria phage P22,P22 Phage,Phage P22,P22 Phages,Phage, P22,Phages, P22
D017510	Protein Folding	Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.	Protein Folding, Globular,Folding, Globular Protein,Folding, Protein,Foldings, Globular Protein,Foldings, Protein,Globular Protein Folding,Globular Protein Foldings,Protein Foldings,Protein Foldings, Globular