scholarly journals Structure of the pneumococcall,d-carboxypeptidase DacB and pathophysiological effects of disabled cell wall hydrolases DacA and DacB

2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Mohammed R. Abdullah ◽  
Javier Gutiérrez-Fernández ◽  
Thomas Pribyl ◽  
Nicolas Gisch ◽  
Malek Saleh ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Wall Hydrolases

Cytochemistry and ultrastructure of the dehiscence zone of almond (Prunus dulcis) fruits

1990 ◽  
Vol 68 (1) ◽  
pp. 63-72 ◽  
Author(s):  
K. Weis ◽  
V. S. Polito
Keyword(s):  
Cell Wall ◽  
Fusion Zone ◽  
Prunus Dulcis ◽  
Epidermal Cells ◽  
Sectioned Material ◽  
Discrete Band ◽  
Dehiscence Zone ◽  
Suture Fusion ◽  
Cell Wall Hydrolases ◽  
Original Line

At maturity, the almond pericarp dehisces along the ventral suture, a region that originates by fusion of epidermal cells and subsequently differentiates into a separation layer. We have characterized the ontogeny of the fusion–dehiscence zone with emphasis on cell wall characteristics by using cytochemical methods for detection of pectin, cutin, cellulose, and lignin to examine the middle lamellae and primary and secondary walls in dehiscence-zone cells. Carpel margins became united postgenitally along opposing epidermal layers giving rise to the suture. Fusion-zone cells host epidermal characteristics, elaborated broad pectinaceous walls, and ultimately formed a discrete band of cells that dehisced along the original line of fusion by dissolution of cell wall pectins. Treatment of treeborne fruits with 1 ppm ethylene gas or extraction of sectioned material with cell wall hydrolases resulted in cell wall changes similar to those in predehiscent fruits.

Simultaneous Inhibition of Two Tomato Fruit Cell Wall Hydrolases, Pectinmethylesterase and Polygalacturonase, with Antisense Gene Constructs

1993 ◽  
Vol 3 (2) ◽  
pp. 181-190 ◽  
Author(s):  
JULIE R. PEAR ◽  
RICK A. SANDERS ◽  
KRISTIN R. SUMMERFELT ◽  
BELINDA MARTINEAU ◽  
WILLIAM R. HIATT
Keyword(s):  
Cell Wall ◽  
Tomato Fruit ◽  
Antisense Gene ◽  
Simultaneous Inhibition ◽  
Cell Wall Hydrolases

scholarly journals Donor-delivered cell wall hydrolases facilitate nanotube penetration into recipient bacteria

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Amit K. Baidya ◽  
Ilan Rosenshine ◽  
Sigal Ben-Yehuda
Keyword(s):  
Cell Wall ◽  
Cell Wall Hydrolases

scholarly journals Insights into Substrate Specificity of NlpC/P60 Cell Wall Hydrolases Containing Bacterial SH3 Domains

mBio ◽  
2015 ◽  
Vol 6 (5) ◽  
Author(s):  
Qingping Xu ◽  
Dominique Mengin-Lecreulx ◽  
Xueqian W. Liu ◽  
Delphine Patin ◽  
Carol L. Farr ◽  
...  
Keyword(s):  
Cell Wall ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Catalytic Domain ◽  
Substrate Binding ◽  
Diaminopimelic Acid ◽  
Single Mutation ◽  
Molecular Architecture ◽  
Substrate Specificities ◽  
Cell Wall Hydrolases

ABSTRACTBacterial SH3 (SH3b) domains are commonly fused with papain-like Nlp/P60 cell wall hydrolase domains. To understand how the modular architecture of SH3b and NlpC/P60 affects the activity of the catalytic domain, three putative NlpC/P60 cell wall hydrolases were biochemically and structurally characterized. These enzymes all have γ-d-Glu-A2pm (A2pm is diaminopimelic acid) cysteine amidase (ordl-endopeptidase) activities but with different substrate specificities. One enzyme is a cell wall lysin that cleaves peptidoglycan (PG), while the other two are cell wall recycling enzymes that only cleave stem peptides with an N-terminall-Ala. Their crystal structures revealed a highly conserved structure consisting of two SH3b domains and a C-terminal NlpC/P60 catalytic domain, despite very low sequence identity. Interestingly, loops from the first SH3b domain dock into the ends of the active site groove of the catalytic domain, remodel the substrate binding site, and modulate substrate specificity. Two amino acid differences at the domain interface alter the substrate binding specificity in favor of stem peptides in recycling enzymes, whereas the SH3b domain may extend the peptidoglycan binding surface in the cell wall lysins. Remarkably, the cell wall lysin can be converted into a recycling enzyme with a single mutation.IMPORTANCEPeptidoglycan is a meshlike polymer that envelops the bacterial plasma membrane and bestows structural integrity. Cell wall lysins and recycling enzymes are part of a set of lytic enzymes that target covalent bonds connecting the amino acid and amino sugar building blocks of the PG network. These hydrolases are involved in processes such as cell growth and division, autolysis, invasion, and PG turnover and recycling. To avoid cleavage of unintended substrates, these enzymes have very selective substrate specificities. Our biochemical and structural analysis of three modular NlpC/P60 hydrolases, one lysin, and two recycling enzymes, show that they may have evolved from a common molecular architecture, where the substrate preference is modulated by local changes. These results also suggest that new pathways for recycling PG turnover products, such as tracheal cytotoxin, may have evolved in bacteria in the human gut microbiome that involve NlpC/P60 cell wall hydrolases.

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