scholarly journals Change of the quantity of penicillin-binding proteins and other cytoplasmic and membrane proteins by mutations of the cell shape-determination genes mreB, mreC, and mreD of Escherichia coli.

1992 ◽  
Vol 38 (2) ◽  
pp. 157-163 ◽  
Author(s):  
YOSHIO OKADA ◽  
MASAAKI WACHI ◽  
KAZUO NAGAI ◽  
MICHIO MATSUHASHI
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Cell Shape ◽  
Binding Proteins ◽  
Penicillin Binding Proteins ◽  
Shape Determination

scholarly journals The Escherichia coli Membrane Protein Insertase YidC Assists in the Biogenesis of Penicillin Binding Proteins

2015 ◽  
Vol 197 (8) ◽  
pp. 1444-1450 ◽  
Author(s):  
Anabela de Sousa Borges ◽  
Jeanine de Keyzer ◽  
Arnold J. M. Driessen ◽  
Dirk-Jan Scheffers
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Binding Proteins ◽  
Protein Complexes ◽  
Specific Cell ◽  
Similar Reduction ◽  
Penicillin Binding Proteins ◽  
Membrane Protein Complexes ◽  
Sec Translocon

ABSTRACTMembrane proteins need to be properly inserted and folded in the membrane in order to perform a range of activities that are essential for the survival of bacteria. The Sec translocon and the YidC insertase are responsible for the insertion of the majority of proteins into the cytoplasmic membrane. YidC can act in combination with the Sec translocon in the insertion and folding of membrane proteins. However, YidC also functions as an insertase independently of the Sec translocon for so-called YidC-only substrates. In addition, YidC can act as a foldase and promote the proper assembly of membrane protein complexes. Here, we investigate the effect ofEscherichia coliYidC depletion on the assembly of penicillin binding proteins (PBPs), which are involved in cell wall synthesis. YidC depletion does not affect the total amount of the specific cell division PBP3 (FtsI) in the membrane, but the amount of active PBP3, as assessed by substrate binding, is reduced 2-fold. A similar reduction in the amount of active PBP2 was observed, while the levels of active PBP1A/1B and PBP5 were essentially similar. PBP1B and PBP3 disappeared from higher-Mwbands upon YidC depletion, indicating that YidC might play a role in PBP complex formation. Taken together, our results suggest that the foldase activity of YidC can extend to the periplasmic domains of membrane proteins.IMPORTANCEThis study addresses the role of the membrane protein insertase YidC in the biogenesis of penicillin binding proteins (PBPs). PBPs are proteins containing one transmembrane segment and a large periplasmic or extracellular domain, which are involved in peptidoglycan synthesis. We observe that in the absence of YidC, two critical PBPs are not correctly folded even though the total amount of protein in the membrane is not affected. Our findings extend the function of YidC as a foldase for membrane protein (complexes) to periplasmic domains of membrane proteins.

scholarly journals Contributions of PBP 5 anddd-Carboxypeptidase Penicillin Binding Proteins to Maintenance of Cell Shape in Escherichia coli

2001 ◽  
Vol 183 (10) ◽  
pp. 3055-3064 ◽  
Author(s):  
David E. Nelson ◽  
Kevin D. Young
Keyword(s):  
Escherichia Coli ◽  
Cell Shape ◽  
Binding Proteins ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
Morphological Defects ◽  
Membrane Anchoring ◽  
Binding Sequence

ABSTRACT Escherichia coli has 12 recognized penicillin binding proteins (PBPs), four of which (PBPs 4, 5, and 6 and DacD) havedd-carboxypeptidase activity. Although the enzymology of the dd-carboxypeptidases has been studied extensively, the in vivo functions of these proteins are poorly understood. To explain why E. coli maintains four independent loci encoding enzymes of considerable sequence identity and comparable in vitro activity, it has been proposed that thedd-carboxypeptidases may substitute for one another in vivo. We tested the validity of this equivalent substitution hypothesis by investigating the effects of these proteins on the aberrant morphology of ΔdacA mutants, which produce no PBP 5. Although cloned PBP 5 complemented the morphological phenotype of a ΔdacA mutant lacking a total of seven PBPs, controlled expression of PBP 4, PBP 6, or DacD did not. Also, a truncated PBP 5 protein lacking its amphipathic C-terminal membrane binding sequence did not reverse the morphological defects and was lethal at low levels of expression, implying that membrane anchoring is essential for the proper functioning of PBP 5. By examining a set of mutants from which multiple PBP genes were deleted, we found that significant morphological aberrations required the absence of at least three different PBPs. The greatest defects were observed in cells lacking, at minimum, PBPs 5 and 6 and one of the endopeptidases (either PBP 4 or PBP 7). The results further differentiate the roles of the low-molecular-weight PBPs, suggest a functional significance for the amphipathic membrane anchor of PBP 5 and, when combined with the recently determined crystal structure of PBP 5, suggest possible mechanisms by which these PBPs may contribute to maintenance of a uniform cell shape in E. coli.

scholarly journals FtsZ Collaborates with Penicillin Binding Proteins To Generate Bacterial Cell Shape in Escherichia coli

2004 ◽  
Vol 186 (20) ◽  
pp. 6768-6774 ◽  
Author(s):  
Archana Varma ◽  
Kevin D. Young
Keyword(s):  
Escherichia Coli ◽  
Cell Shape ◽  
Binding Proteins ◽  
Structural Integrity ◽  
Morphological Diversity ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Penicillin Binding Proteins ◽  
Bacterial Cell Shape ◽  
Defective Sites

ABSTRACT The mechanisms by which bacteria adopt and maintain individual shapes remain enigmatic. Outstanding questions include why cells are a certain size, length, and width; why they are uniform or irregular; and why some branch while others do not. Previously, we showed that Escherichia coli mutants lacking multiple penicillin binding proteins (PBPs) display extensive morphological diversity. Because defective sites in these cells exhibit the structural and functional characteristics of improperly localized poles, we investigated the connection between cell division and shape. Here we show that under semipermissive conditions the temperature-sensitive FtsZ84 protein produces branched and aberrant cells at a high frequency in mutants lacking PBP 5, and this phenotype is exacerbated by the loss of additional peptidoglycan endopeptidases. Surprisingly, certain ftsZ84 strains lyse at the nonpermissive temperature instead of filamenting, and inhibition of wild-type FtsZ forces some mutants into tightly wound spirillum-like morphologies. The results demonstrate that significant aspects of bacterial shape are dictated by a previously unrecognized relationship between the septation machinery and ostensibly minor peptidoglycan-modifying enzymes and that under certain circumstances improper FtsZ function can destroy the structural integrity of the cell.

scholarly journals Enterobactin- and salmochelin-β-lactam conjugates induce cell morphologies consistent with inhibition of penicillin-binding proteins in uropathogenic Escherichia coli CFT073

2021 ◽  
Author(s):  
Artur Sargun ◽  
Timothy C. Johnstone ◽  
Hui Zhi ◽  
Manuela Raffatellu ◽  
Elizabeth M. Nolan
Keyword(s):  
Escherichia Coli ◽  
Binding Proteins ◽  
Uropathogenic Escherichia Coli ◽  
Penicillin Binding Proteins ◽  
E Coli

Siderophore-β-lactam conjugates based on enterobactin and diglucosylated enterobactin enter the periplasm of uropathogenic E. coli CFT073 via the FepA and IroN transporters, and target penicillin-binding proteins.

The use of a Mercury-Penicillin V Derivative to Localize Penicillin-Binding Proteins in Escherichia coli

1993 ◽  
pp. 295-301
Author(s):  
Terry R. Paul ◽  
Terry J. Beveridge ◽  
Noreen G. Halligan ◽  
Larry C. Blaszczak ◽  
Tom R. Parr
Keyword(s):  
Escherichia Coli ◽  
Binding Proteins ◽  
Penicillin Binding Proteins ◽  
Penicillin V
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