scholarly journals A lysozyme with altered substrate specificity facilitates prey cell exit by the periplasmic predator Bdellovibrio bacteriovorus

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher J. Harding ◽  
Simona G. Huwiler ◽  
Hannah Somers ◽  
Carey Lambert ◽  
Luke J. Ray ◽  
...  
Keyword(s):  
Cell Wall ◽  
Substrate Specificity ◽  
Ex Vivo ◽  
Prey Cell ◽  
Bdellovibrio Bacteriovorus ◽  
Chemical Difference ◽  
Important Chemical ◽  
Biochemical Assays

Abstract Lysozymes are among the best-characterized enzymes, acting upon the cell wall substrate peptidoglycan. Here, examining the invasive bacterial periplasmic predator Bdellovibrio bacteriovorus, we report a diversified lysozyme, DslA, which acts, unusually, upon (GlcNAc-) deacetylated peptidoglycan. B. bacteriovorus are known to deacetylate the peptidoglycan of the prey bacterium, generating an important chemical difference between prey and self walls and implying usage of a putative deacetyl-specific “exit enzyme”. DslA performs this role, and ΔDslA strains exhibit a delay in leaving from prey. The structure of DslA reveals a modified lysozyme superfamily fold, with several adaptations. Biochemical assays confirm DslA specificity for deacetylated cell wall, and usage of two glutamate residues for catalysis. Exogenous DslA, added ex vivo, is able to prematurely liberate B. bacteriovorus from prey, part-way through the predatory lifecycle. We define a mechanism for specificity that invokes steric selection, and use the resultant motif to identify wider DslA homologues.

scholarly journals Synthesis of Lipid-Carbohydrate-Peptidyl-RNA Conjugates to Explore the Limits Imposed by the Substrate Specificity of Cell Wall Enzymes on the Acquisition of Drug Resistance

2018 ◽  
Vol 24 (56) ◽  
pp. 14911-14915 ◽  
Author(s):  
Matthieu Fonvielle ◽  
Ahmed Bouhss ◽  
Coralie Hoareau ◽  
Delphine Patin ◽  
Dominique Mengin-Lecreulx ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Wall ◽  
Substrate Specificity ◽  
Cell Wall Enzymes

scholarly journals The endogenous galactofuranosidase GlfH1 hydrolyzes mycobacterial arabinogalactan

2020 ◽  
Vol 295 (15) ◽  
pp. 5110-5123 ◽  
Author(s):  
Lin Shen ◽  
Albertus Viljoen ◽  
Sydney Villaume ◽  
Maju Joe ◽  
Iman Halloum ◽  
...  
Keyword(s):  
Cell Wall ◽  
Structural Changes ◽  
Cell Envelope ◽  
Wall Structure ◽  
Tubercle Bacillus ◽  
Bioinformatics Analyses ◽  
The Past ◽  
Biochemical Assays ◽  
Mycobacterial Protein

Despite impressive progress made over the past 20 years in our understanding of mycolylarabinogalactan-peptidoglycan (mAGP) biogenesis, the mechanisms by which the tubercle bacillus Mycobacterium tuberculosis adapts its cell wall structure and composition to various environmental conditions, especially during infection, remain poorly understood. Being the central portion of the mAGP complex, arabinogalactan (AG) is believed to be the constituent of the mycobacterial cell envelope that undergoes the least structural changes, but no reports exist supporting this assumption. Herein, using recombinantly expressed mycobacterial protein, bioinformatics analyses, and kinetic and biochemical assays, we demonstrate that the AG can be remodeled by a mycobacterial endogenous enzyme. In particular, we found that the mycobacterial GlfH1 (Rv3096) protein exhibits exo-β-d-galactofuranose hydrolase activity and is capable of hydrolyzing the galactan chain of AG by recurrent cleavage of the terminal β-(1,5) and β-(1,6)-Galf linkages. The characterization of this galactosidase represents a first step toward understanding the remodeling of mycobacterial AG.

scholarly journals Author Correction: Fluorescent d-amino-acids reveal bi-cellular cell wall modifications important for Bdellovibrio bacteriovorus predation

2018 ◽  
Vol 3 (2) ◽  
pp. 254-254 ◽  
Author(s):  
Erkin Kuru ◽  
Carey Lambert ◽  
Jonathan Rittichier ◽  
Rob Till ◽  
Adrien Ducret ◽  
...  
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Bdellovibrio Bacteriovorus

scholarly journals Preliminary crystallographic study of theStreptococcus agalactiaesortases, sortase A and sortase C1

2010 ◽  
Vol 66 (9) ◽  
pp. 1096-1100 ◽  
Author(s):  
Baldeep Khare ◽  
Alexandra Samal ◽  
Krishnan Vengadesan ◽  
K. R. Rajashankar ◽  
Xin Ma ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Substrate Specificity ◽  
Streptococcus Agalactiae ◽  
Crystal Form ◽  
Sortase A ◽  
Crystal Forms ◽  
Gram Positive Bacteria ◽  
Crystallographic Study ◽  
Surface Adhesins

Sortases are cysteine transpeptidases that are essential for the assembly and anchoring of cell-surface adhesins in Gram-positive bacteria. InStreptococcus agalactiae(GBS), the pilin-specific sortase SrtC1 catalyzes the polymerization of pilins encoded by pilus island 1 (PI-1) and the housekeeping sortase SrtA is necessary for cell-wall anchoring of the resulting pilus polymers. These sortases are known to utilize different substrates for pilus polymerization and cell-wall anchoring; however, the structural correlates that dictate their substrate specificity have not yet been clearly defined. This report presents the expression, purification and crystallization of SrtC1 (SAG0647) and SrtA (SAG0961) fromS. agalactiaestrain 2603V/R. The GBS SrtC1 has been crystallized in three crystal forms and the GBS SrtA has been crystallized in one crystal form.

scholarly journals Cell wall substrate specificity of six different lysozymes and lysozyme inhibitory activity of bacterial extracts

2006 ◽  
Vol 259 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Dorothy Nakimbugwe ◽  
Barbara Masschalck ◽  
Daphne Deckers ◽  
Lien Callewaert ◽  
Abram Aertsen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Substrate Specificity ◽  
Inhibitory Activity

scholarly journals Investigation of the substrate specificity of a cloned expressed human bilirubin UDP-glucuronosyltransferase: UDP-sugar specificity and involvement in steroid and xenobiotic glucuronidation

1994 ◽  
Vol 303 (1) ◽  
pp. 233-240 ◽  
Author(s):  
S B Senafi ◽  
D J Clarke ◽  
B Burchell
Keyword(s):  
Substrate Specificity ◽  
Ex Vivo ◽  
Liver Microsomes ◽  
Chinese Hamster ◽  
Genetically Engineered ◽  
Transport Processes ◽  
Chemical Structures ◽  
Catalytic Potential ◽  
Chinese Hamster V79 Cells ◽  
Udp Glucuronosyltransferase

A cloned human bilirubin UDP-glucuronosyltransferase (UGT) stably expressed in Chinese hamster V79 cells was used to assess the substrate specificity of the enzyme. The catalytic potential (Vmax/Km(bilirubin) of the enzyme with UDP-glucuronic acid (UDPGA) was 2-fold and 10-fold greater than that for UDP-xylose and UDP-glucose respectively. The formation of bilirubin mono- and di-conjugates was found to be dependent on time, UDP-sugar concentration and bilirubin concentration. Ex vivo studies demonstrated that the genetically engineered cell line was capable of the uptake and glucuronidation of bilirubin and the release of bilirubin glucuronide, indicating its usefulness in studying transport processes. Over 100 compounds, including drugs, xenobiotics and endogenous steroids, were tested as substrates for the enzyme to determine the chemical structures accepted as substrates. A wide diversity of xenobiotic compounds such as phenols, anthraquinones and flavones (many of which are in foodstuffs) were glucuronidated by the enzyme. The enzyme also had the capacity to glucuronidate oestriols and oestradiols stereoselectively. H.p.l.c. analysis of the regioselective glucuronidation of beta-oestradiol (E2) demonstrated that it was conjugated solely at its A-ring hydroxy group by the bilirubin UGT to form E2-3-glucuronide, this was in contrast with human liver microsomes which formed 3- and 17-glucuronides of this oestrogen. Studies utilizing microsomes from a Crigler-Najjar patient and inhibition of E2 glucuronidation with bilirubin indicated that the cloned expressed bilirubin UGT was the major human UGT isoform responsible for the formation of E2-3-glucuronide, which is the predominant E2 conjugate in human urine.

scholarly journals Microbe Profile: Bdellovibrio bacteriovorus: a specialized bacterial predator of bacteria

Microbiology ◽  
2021 ◽  
Vol 167 (4) ◽  
Author(s):  
Andrew L. Lovering ◽  
R. Elizabeth Sockett
Keyword(s):  
Type Species ◽  
Free Living ◽  
Prey Cell ◽  
Bdellovibrio Bacteriovorus ◽  
Content Type ◽  
Link Type ◽  
Attack Phase ◽  
Future Potential ◽  
Basic Biology ◽  
The Way

Bdellovibrio bacteriovorus is an environmentally-ubiquitous bacterium that uses unique adaptations to kill other bacteria. The best-characterized strain, HD100, has a multistage lifestyle, with both a free-living attack phase and an intraperiplasmic growth and division phase inside the prey cell. Advances in understanding the basic biology and regulation of predation processes are paving the way for future potential therapeutic and bioremediation applications of this unusual bacterium.

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