Chemical Modifications of Escherichia coli Ribosomal Proteins S4, S7, and S8 in Regard to Their Capacity for Binding 16 S RNA

1974 ◽  
Vol 52 (11) ◽  
pp. 1038-1043 ◽  
Author(s):  
Gérald Lemieux
Keyword(s):  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Binding Capacity ◽  
Cysteine Residue ◽  
Amino Groups ◽  
Chemical Modifications ◽  
Specific Chemical ◽  
Rna Interaction ◽  
Rna Complex ◽  
Rna Complexes

Mild specific chemical modifications were used to test the possible role of cysteines, tyrosines, and amino groups of ribosomal proteins S4, S7, and S8 for binding to 16 S RNA (Escherichia coli). The single cysteine residue present in proteins S4 and S8 is not directly involved in the binding process with RNA. The protein S7 does not contain cysteine. Total nitration of tyrosines in S4, S7, and S8 abolishes the binding capacity of these proteins. However, when the modification is done with the preformed protein–RNA complexes, some protection occurs. Two amino groups could be reacted in free S8 as well as in an S8–RNA complex. This modification does not influence protein–RNA interaction. Proteins S4, S7, and S8 in Regard to Their Capacity for Binding 16 S RNA. Can. J. Biochem. 52, modified. A new method for the stoichiometric determination of single protein–RNA complexes is presented.

scholarly journals Ubiquilin 2 modulates ALS/FTD-linked FUS–RNA complex dynamics and stress granule formation

2018 ◽  
Vol 115 (49) ◽  
pp. E11485-E11494 ◽  
Author(s):  
Elizabeth J. Alexander ◽  
Amirhossein Ghanbari Niaki ◽  
Tao Zhang ◽  
Jaya Sarkar ◽  
Yang Liu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Complex Dynamics ◽  
Low Complexity ◽  
Stress Granule ◽  
Granule Formation ◽  
Single Molecule Level ◽  
Rna Interaction ◽  
Rna Complex ◽  
Rna Complexes

The ubiquitin-like protein ubiquilin 2 (UBQLN2) has been genetically and pathologically linked to the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but its normal cellular functions are not well understood. In a search for UBQLN2-interacting proteins, we found an enrichment of stress granule (SG) components, including ALS/FTD-linked heterogeneous ribonucleoprotein fused in sarcoma (FUS). Through the use of an optimized SG detection method, we observed UBQLN2 and its interactors at SGs. A low complexity, Sti1-like repeat region in UBQLN2 was sufficient for its localization to SGs. Functionally, UBQLN2 negatively regulated SG formation. UBQLN2 increased the dynamics of FUS–RNA interaction and promoted the fluidity of FUS–RNA complexes at a single-molecule level. This solubilizing effect corresponded to a dispersal of FUS liquid droplets in vitro and a suppression of FUS SG formation in cells. ALS-linked mutations in UBQLN2 reduced its association with FUS and impaired its function in regulating FUS–RNA complex dynamics and SG formation. These results reveal a previously unrecognized role for UBQLN2 in regulating the early stages of liquid–liquid phase separation by directly modulating the fluidity of protein–RNA complexes and the dynamics of SG formation.

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

Posttranslational Modifications of Ribosomal Proteins in Escherichia coli

Acta Naturae ◽  
2011 ◽  
Vol 3 (2) ◽  
pp. 22-33 ◽  
Author(s):  
M V Nesterchuk ◽  
P V Sergiev ◽  
O A Dontsova
Keyword(s):  
Escherichia Coli ◽  
Posttranslational Modifications ◽  
Ribosomal Proteins

scholarly journals Structure of Escherichia coli dnaC. Identification of a cysteine residue possibly involved in association with dnaB protein.

1987 ◽  
Vol 262 (22) ◽  
pp. 10475-10480 ◽  
Author(s):  
N Nakayama ◽  
M W Bond ◽  
A Miyajima ◽  
J Kobori ◽  
K Arai
Keyword(s):  
Escherichia Coli ◽  
Cysteine Residue
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