scholarly journals The pseudouridine synthase RluD is required for normal ribosome assembly and function in Escherichia coli

RNA ◽  
2005 ◽  
Vol 11 (7) ◽  
pp. 1141-1152 ◽  
Author(s):  
N. S. GUTGSELL
2015 ◽  
Vol 197 (10) ◽  
pp. 1819-1827 ◽  
Author(s):  
Promisree Choudhury ◽  
Ann M. Flower

ABSTRACTThe bacterial BipA protein belongs to the EF-G family of translational GTPases and has been postulated to be either a regulatory translation factor or a ribosome assembly factor. To distinguish between these hypotheses, we analyzed the effect ofbipAdeletion on three phenotypes associated with ribosome assembly factors: cold sensitivity, ribosome subunit distribution, and rRNA processing. We demonstrated that a ΔbipAstrain exhibits a cold-sensitive phenotype that is similar to, and synergistic with, that of a strain with a known ribosome assembly factor,deaD. Additionally, thebipAdeletion strain displayed a perturbed ribosome subunit distribution when grown at low temperature, similar to that of adeaDmutant, and again, the double mutant showed additive effects. The primary ribosomal deficiency noted was a decreased level of the 50S subunit and the appearance of a presumed pre-50S particle. Finally, deletion ofbipAresulted in accumulation of pre23S rRNA, as did deletion ofdeaD. We further found that deletion ofrluC, which encodes a pseudouridine synthase that modifies the 23S rRNA at three sites, suppressed all three phenotypes of thebipAmutant, supporting and extending previous findings. Together, these results suggest that BipA is important for the correct and efficient assembly of the 50S subunit of the ribosome at low temperature but when unmodified by RluC, the ribosomes become BipA independent for assembly.IMPORTANCEThe ribosome is the complex ribonucleoprotein machine responsible for protein synthesis in all cells. Although much has been learned about the structure and function of the ribosome, we do not fully understand how it is assembled or the accessory proteins that increase efficiency of biogenesis and function. This study examined one such protein, BipA. Our results indicate that BipA either directly or indirectly enhances the formation of the 50S subunit of the ribosome, particularly at low temperature. In addition, ribosomes contain a large number of modified nucleosides, including pseudouridines. This work demonstrates that the function of BipA is tied to the modification status of the ribosome and may help us understand why these modifications have been retained.


1992 ◽  
Vol 267 (3) ◽  
pp. 1712-1718 ◽  
Author(s):  
J Weber ◽  
R S Lee ◽  
E Grell ◽  
J G Wise ◽  
A E Senior

2021 ◽  
Vol 22 (9) ◽  
pp. 4359
Author(s):  
Sara Martín-Villanueva ◽  
Gabriel Gutiérrez ◽  
Dieter Kressler ◽  
Jesús de la Cruz

Ubiquitin is a small protein that is highly conserved throughout eukaryotes. It operates as a reversible post-translational modifier through a process known as ubiquitination, which involves the addition of one or several ubiquitin moieties to a substrate protein. These modifications mark proteins for proteasome-dependent degradation or alter their localization or activity in a variety of cellular processes. In most eukaryotes, ubiquitin is generated by the proteolytic cleavage of precursor proteins in which it is fused either to itself, constituting a polyubiquitin precursor, or as a single N-terminal moiety to ribosomal proteins, which are practically invariably eL40 and eS31. Herein, we summarize the contribution of the ubiquitin moiety within precursors of ribosomal proteins to ribosome biogenesis and function and discuss the biological relevance of having maintained the explicit fusion to eL40 and eS31 during evolution. There are other ubiquitin-like proteins, which also work as post-translational modifiers, among them the small ubiquitin-like modifier (SUMO). Both ubiquitin and SUMO are able to modify ribosome assembly factors and ribosomal proteins to regulate ribosome biogenesis and function. Strikingly, ubiquitin-like domains are also found within two ribosome assembly factors; hence, the functional role of these proteins will also be highlighted.


1970 ◽  
Vol 117 (3) ◽  
pp. 623-631 ◽  
Author(s):  
Volker Neuhoff ◽  
Wolf-Bernhard Schill ◽  
Hans Sternbach

By using micro disc electrophoresis and micro-diffusion techniques, the interaction of pure DNA-dependent RNA polymerase (EC 2.7.7.6) from Escherichia coli with the template, the substrates and the inhibitors heparin and rifampicin was investigated. The following findings were obtained: (1) heparin converts the 24S and 18S particles of the polymerase into the 13S form; (2) heparin inhibits RNA synthesis by dissociating the enzyme–template complex; (3) rifampicin does not affect the attachment of heparin to the enzyme; (4) the substrates ATP and UTP are bound by enzyme loaded with rifampicin; (5) rifampicin is bound by an enzyme–template complex to the same extent as by an RNA-synthesizing enzyme–template complex. From this it is concluded that the mechanism of the inhibition of RNA synthesis by rifampicin is radically different from that by heparin. As a working hypothesis to explain the inhibitory mechanism of rifampicin, it is assumed that it becomes very firmly attached to a position close to the synthesizing site and only blocks this when no synthesis is in progress.


Microbiology ◽  
1982 ◽  
Vol 128 (5) ◽  
pp. 997-1001
Author(s):  
P. D. Butler ◽  
P. F. G. Sims ◽  
D. G. Wild

2006 ◽  
Vol 188 (6) ◽  
pp. 2163-2172 ◽  
Author(s):  
Paul W. King ◽  
Matthew C. Posewitz ◽  
Maria L. Ghirardi ◽  
Michael Seibert

ABSTRACT Maturation of [FeFe] hydrogenases requires the biosynthesis and insertion of the catalytic iron-sulfur cluster, the H cluster. Two radical S-adenosylmethionine (SAM) proteins proposed to function in H cluster biosynthesis, HydEF and HydG, were recently identified in the hydEF-1 mutant of the green alga Chlamydomonas reinhardtii (M. C. Posewitz, P. W. King, S. L. Smolinski, L. Zhang, M. Seibert, and M. L. Ghirardi, J. Biol. Chem. 279:25711-25720, 2004). Previous efforts to study [FeFe] hydrogenase maturation in Escherichia coli by coexpression of C. reinhardtii HydEF and HydG and the HydA1 [FeFe] hydrogenase were hindered by instability of the hydEF and hydG expression clones. A more stable [FeFe] hydrogenase expression system has been achieved in E. coli by cloning and coexpression of hydE, hydF, and hydG from the bacterium Clostridium acetobutylicum. Coexpression of the C. acetobutylicum maturation proteins with various algal and bacterial [FeFe] hydrogenases in E. coli resulted in purified enzymes with specific activities that were similar to those of the enzymes purified from native sources. In the case of structurally complex [FeFe] hydrogenases, maturation of the catalytic sites could occur in the absence of an accessory iron-sulfur cluster domain. Initial investigations of the structure and function of the maturation proteins HydE, HydF, and HydG showed that the highly conserved radical-SAM domains of both HydE and HydG and the GTPase domain of HydF were essential for achieving biosynthesis of active [FeFe] hydrogenases. Together, these results demonstrate that the catalytic domain and a functionally complete set of Hyd maturation proteins are fundamental to achieving biosynthesis of catalytic [FeFe] hydrogenases.


2008 ◽  
Vol 74 (24) ◽  
pp. 7821-7823 ◽  
Author(s):  
Kai Linke ◽  
Nagarajan Periasamy ◽  
Matthias Ehrmann ◽  
Roland Winter ◽  
Rudi F. Vogel

ABSTRACT High hydrostatic pressure (HHP) is suggested to influence the structure and function of membranes and/or integrated proteins. We demonstrate for the first time HHP-induced dimer dissociation of membrane proteins in vivo with Vibrio cholerae ToxR variants in Escherichia coli reporter strains carrying ctx::lacZ fusions. Dimerization ceased at 20 to 50 MPa depending on the nature of the transmembrane segments rather than on changes in the ToxR lipid bilayer environment.


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