Limits...
Giving structure to the biofilm matrix: an overview of individual strategies and emerging common themes.

Hobley L, Harkins C, MacPhee CE, Stanley-Wall NR - FEMS Microbiol. Rev. (2015)

Bottom Line: This matrix fulfils a variety of functions for the community, from providing structural rigidity and protection from the external environment to controlling gene regulation and nutrient adsorption.We highlight recent advances in the understanding of the structural and functional role that carbohydrates and proteins play within the biofilm matrix to provide three-dimensional architectural integrity and functionality to the biofilm community.We highlight, where relevant, experimental techniques that are allowing the boundaries of our understanding of the biofilm matrix to be extended using Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis as exemplars.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.

Show MeSH

Related in: MedlinePlus

Structure of the CWA proteins. All CWA proteins contain a Sec-dependent secretory signal sequence, a C-terminal LPXTG sortase motif, a hydrophobic domain and finally a chain of positively charged residues at the end of the C-terminus. (A) The schematic demonstrates the typical domain structure within the MSCRAMM family of CWAs. At the N-terminus, a Sec-dependent signal sequence followed by a variable number of binding domains that begin with an N-terminal A domain (inclusive of N subdomains in the case of FnBPs (B and C) and ClfB). These are followed by a wall-spanning region, the LPXTG motif and finally a membrane-spanning region. (D) In SasG, the binding domain is subdivided into the N-terminal A domain and a varying number of G5/E repeats.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4551309&req=5

fig6: Structure of the CWA proteins. All CWA proteins contain a Sec-dependent secretory signal sequence, a C-terminal LPXTG sortase motif, a hydrophobic domain and finally a chain of positively charged residues at the end of the C-terminus. (A) The schematic demonstrates the typical domain structure within the MSCRAMM family of CWAs. At the N-terminus, a Sec-dependent signal sequence followed by a variable number of binding domains that begin with an N-terminal A domain (inclusive of N subdomains in the case of FnBPs (B and C) and ClfB). These are followed by a wall-spanning region, the LPXTG motif and finally a membrane-spanning region. (D) In SasG, the binding domain is subdivided into the N-terminal A domain and a varying number of G5/E repeats.

Mentions: In S. aureus, the expression of CWA proteins is integral to the ability of the organism to attach to a surface and thereby initiate biofilm formation (Fig. 5). At the molecular level, CWA proteins are characterized by the presence of a Sec-dependent secretory signal sequence at the N-terminus and contain an ‘LPXTG’ motif at the C-terminus (Fig. 6A). Upon secretion, the proteins are cleaved by Sortase A (SrtA), a membrane-bound transpeptidase, which catalyses the attachment of the processed protein to the cell wall peptidoglycan (Ton-That et al.1999). S. aureus encodes up to 24 different CWAs and there can be significant variation in expression between strains and in a growth condition-specific manner (Foster et al.2014). For example, strain ‘Newman’ is a clinical isolate that forms weak biofilms, most likely as it carries mutations in the coding regions for the Fnbp proteins (vide infra) (Grundmeier et al.2004). To date, the CWA family of proteins has been the most extensively studied with respect to their function as biofilm-associated factors that bind ligands on cell surfaces to allow adhesion.


Giving structure to the biofilm matrix: an overview of individual strategies and emerging common themes.

Hobley L, Harkins C, MacPhee CE, Stanley-Wall NR - FEMS Microbiol. Rev. (2015)

Structure of the CWA proteins. All CWA proteins contain a Sec-dependent secretory signal sequence, a C-terminal LPXTG sortase motif, a hydrophobic domain and finally a chain of positively charged residues at the end of the C-terminus. (A) The schematic demonstrates the typical domain structure within the MSCRAMM family of CWAs. At the N-terminus, a Sec-dependent signal sequence followed by a variable number of binding domains that begin with an N-terminal A domain (inclusive of N subdomains in the case of FnBPs (B and C) and ClfB). These are followed by a wall-spanning region, the LPXTG motif and finally a membrane-spanning region. (D) In SasG, the binding domain is subdivided into the N-terminal A domain and a varying number of G5/E repeats.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4551309&req=5

fig6: Structure of the CWA proteins. All CWA proteins contain a Sec-dependent secretory signal sequence, a C-terminal LPXTG sortase motif, a hydrophobic domain and finally a chain of positively charged residues at the end of the C-terminus. (A) The schematic demonstrates the typical domain structure within the MSCRAMM family of CWAs. At the N-terminus, a Sec-dependent signal sequence followed by a variable number of binding domains that begin with an N-terminal A domain (inclusive of N subdomains in the case of FnBPs (B and C) and ClfB). These are followed by a wall-spanning region, the LPXTG motif and finally a membrane-spanning region. (D) In SasG, the binding domain is subdivided into the N-terminal A domain and a varying number of G5/E repeats.
Mentions: In S. aureus, the expression of CWA proteins is integral to the ability of the organism to attach to a surface and thereby initiate biofilm formation (Fig. 5). At the molecular level, CWA proteins are characterized by the presence of a Sec-dependent secretory signal sequence at the N-terminus and contain an ‘LPXTG’ motif at the C-terminus (Fig. 6A). Upon secretion, the proteins are cleaved by Sortase A (SrtA), a membrane-bound transpeptidase, which catalyses the attachment of the processed protein to the cell wall peptidoglycan (Ton-That et al.1999). S. aureus encodes up to 24 different CWAs and there can be significant variation in expression between strains and in a growth condition-specific manner (Foster et al.2014). For example, strain ‘Newman’ is a clinical isolate that forms weak biofilms, most likely as it carries mutations in the coding regions for the Fnbp proteins (vide infra) (Grundmeier et al.2004). To date, the CWA family of proteins has been the most extensively studied with respect to their function as biofilm-associated factors that bind ligands on cell surfaces to allow adhesion.

Bottom Line: This matrix fulfils a variety of functions for the community, from providing structural rigidity and protection from the external environment to controlling gene regulation and nutrient adsorption.We highlight recent advances in the understanding of the structural and functional role that carbohydrates and proteins play within the biofilm matrix to provide three-dimensional architectural integrity and functionality to the biofilm community.We highlight, where relevant, experimental techniques that are allowing the boundaries of our understanding of the biofilm matrix to be extended using Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis as exemplars.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.

Show MeSH
Related in: MedlinePlus