Construction and Application of an Escherichia coli Strain Lacking 62 Genes Responsible for the Biosynthesis of Enterobacterial Common Antigen and Flagella

2021 ◽  
Author(s):  
Jun Qiao ◽  
Xin Tan ◽  
Danyang Huang ◽  
Hedan Li ◽  
Zhen Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Coli Strain ◽  
Common Antigen ◽  
Enterobacterial Common Antigen

Occurrence and structure of cyclic Enterobacterial Common Antigen in Escherichia coli O157:H−

2012 ◽  
Vol 363 ◽  
pp. 29-32 ◽  
Author(s):  
Eleonora Fregolino ◽  
Radka Ivanova ◽  
Rosa Lanzetta ◽  
Antonio Molinaro ◽  
Michelangelo Parrilli ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Common Antigen ◽  
Enterobacterial Common Antigen

scholarly journals Mutations in enterobacterial common antigen biosynthesis restore outer membrane barrier function in Escherichia coli tol-pal mutants

2018 ◽  
Author(s):  
Xiang’Er Jiang ◽  
Wee Boon Tan ◽  
Rahul Shrivastava ◽  
Deborah Chwee San Seow ◽  
Swaine Lin Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Barrier Function ◽  
Lipid Homeostasis ◽  
Common Antigen ◽  
Potential Mechanism ◽  
External Threats ◽  
Enterobacterial Common Antigen ◽  
Lipid Species ◽  
Membrane Barrier

SummaryThe outer membrane (OM) is an essential component of the Gram-negative bacterial envelope that protects cells against external threats. To maintain a functional OM, cells require distinct mechanisms to ensure balance of proteins and lipids in the membrane. Mutations in OM biogenesis and/or homeostasis pathways often result in permeability defects, but how molecular changes in the OM affect barrier function is unclear. Here, we seek potential mechanism(s) that can alleviate permeability defects in Escherichia coli cells lacking the Tol-Pal complex, which accumulate excess PLs in the OM. We identify mutations in enterobacterial common antigen (ECA) biosynthesis that re-establish OM barrier function against large hydrophilic molecules, yet did not restore lipid homeostasis. Furthermore, we demonstrate that build-up of biosynthetic intermediates, but not loss of ECA itself, contributes to the rescue. This suppression of OM phenotypes is unrelated to known effects that accumulation of ECA intermediates have on the cell wall. Finally, we reveal that an unusual diacylglycerol pyrophosphoryl-linked lipid species also accumulates in ECA mutants, and might play a role in the rescue phenotype. Our work provides insights into how OM barrier function can be restored independent of lipid homeostasis, and highlights previously unappreciated effects of ECA-related species in OM biology.

scholarly journals Crystal Structure of TDP-Fucosamine Acetyltransferase (WecD) from Escherichia coli, an Enzyme Required for Enterobacterial Common Antigen Synthesis

2006 ◽  
Vol 188 (15) ◽  
pp. 5606-5617 ◽  
Author(s):  
Ming-Ni Hung ◽  
Erumbi Rangarajan ◽  
Christine Munger ◽  
Guy Nadeau ◽  
Traian Sulea ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Coenzyme A ◽  
Structural Data ◽  
Enteric Bacteria ◽  
Common Antigen ◽  
Acetyl Coa ◽  
Enterobacterial Common Antigen ◽  
Thiolate Anion ◽  
Acetyl Transfer

ABSTRACT Enterobacterial common antigen (ECA) is a polysaccharide found on the outer membrane of virtually all gram-negative enteric bacteria and consists of three sugars, N-acetyl-d-glucosamine, N-acetyl-d-mannosaminuronic acid, and 4-acetamido-4,6-dideoxy-d-galactose, organized into trisaccharide repeating units having the sequence →3)-α-d-Fuc4NAc-(1→4)-β-d-ManNAcA-(1→4)-α-d-GlcNAc-(1→. While the precise function of ECA is unknown, it has been linked to the resistance of Shiga-toxin-producing Escherichia coli (STEC) O157:H7 to organic acids and the resistance of Salmonella enterica to bile salts. The final step in the synthesis of 4-acetamido-4,6-dideoxy-d-galactose, the acetyl-coenzyme A (CoA)-dependent acetylation of the 4-amino group, is carried out by TDP-fucosamine acetyltransferase (WecD). We have determined the crystal structure of WecD in apo form at a 1.95-Å resolution and bound to acetyl-CoA at a 1.66-Å resolution. WecD is a dimeric enzyme, with each monomer adopting the GNAT N-acetyltransferase fold, common to a number of enzymes involved in acetylation of histones, aminoglycoside antibiotics, serotonin, and sugars. The crystal structure of WecD, however, represents the first structure of a GNAT family member that acts on nucleotide sugars. Based on this cocrystal structure, we have used flexible docking to generate a WecD-bound model of the acetyl-CoA-TDP-fucosamine tetrahedral intermediate, representing the structure during acetyl transfer. Our structural data show that WecD does not possess a residue that directly functions as a catalytic base, although Tyr208 is well positioned to function as a general acid by protonating the thiolate anion of coenzyme A.

Sign in / Sign up

Export Citation Format

Share Document