Biomaterial Database

Dimerization by colicin E3 in the absence of immunity protein. 1983

B L Levinson, and C A Pickover, and F M Richards

Using small angle x-ray scattering from solutions of colicin E3-immunity protein complex and the separated proteins, we have measured the radii of gyration of each species. We find that the complex is an elongated molecule with a radius of gyration of 35.5 +/- 0.7 A. Immunity protein is more compact with a radius of gyration of 13.4 +/- 0.1 A. Upon removal of immunity protein from the complex, colicin E3 (form minus immunity protein) undergoes further elongation and dimerizes, such that its radius of gyration increases to 75.6 +/- 3.1 A. Dimerization is not reversed by simple addition of a stoichiometric amount of immunity protein to the E3 solution, even though this is sufficient to block in vitro activity. We suggest that the elongation, and perhaps dimer formation, occurs in vivo, concomitant with membrane translocation.

UI	MeSH Term	Description	Entries
D003087	Colicins	Bacteriocins elaborated by strains of Escherichia coli and related species. They are proteins or protein-lipopolysaccharide complexes lethal to other strains of the same species.	Colicin,Colicin E9,Colicine,Colicines,Colicin A,Colicin B,Colicin E,Colicin E1,Colicin E2,Colicin E3,Colicin E8,Colicin HSC10,Colicin Ia,Colicin Ib,Colicin K,Colicin K-K235,Colicin M,Colicin N,Colicin V,Colicins E,Colicins E9,Precolicin E1,Colicin K K235,E9, Colicin
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
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D012542	Scattering, Radiation	The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Radiation Scattering,Radiation Scatterings,Scatterings, Radiation
D014965	X-Rays	Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.	Grenz Ray,Grenz Rays,Roentgen Ray,Roentgen Rays,X Ray,X-Ray,Xray,Radiation, X,X-Radiation,Xrays,Ray, Grenz,Ray, Roentgen,Ray, X,Rays, Grenz,Rays, Roentgen,Rays, X,X Radiation,X Rays,X-Radiations
D046911	Macromolecular Substances	Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.	Macromolecular Complexes,Macromolecular Compounds,Macromolecular Compounds and Complexes,Complexes, Macromolecular,Compounds, Macromolecular,Substances, Macromolecular
D029968	Escherichia coli Proteins	Proteins obtained from ESCHERICHIA COLI.	E coli Proteins