Sticking to the Subject: Multifunctionality in Microbial Adhesins

Area of Science:

• Microbiology
• Molecular Biology
• Structural Biology

Background:

• Microbial adhesins mediate critical processes like aggregation, biofilm formation, and host adhesion.
• Adhesins are classified into 'professional' and 'moonlighting' types, distinguished by conserved non-adhesive activities and dissociation rates.

Purpose of the Study:

• To categorize microbial adhesins based on their functions and dissociation rates.
• To explore the diverse activities and structural features of professional adhesins.
• To compare professional and moonlighting adhesins.

Main Methods:

• Comparative analysis of adhesin classes (professional vs. moonlighting).
• Review of structural features contributing to adhesin multifunctionality.
• Case studies including *Bacillus subtilis* TasA, pilin adhesins, MSCRAMMs, and yeast/ *Candida* adhesins.

Main Results:

• Professional adhesins possess distinct, often prolonged, dissociation rates compared to moonlighting adhesins.
• Adhesins exhibit at least three core activities: cell surface association, ligand binding, and host recognition.
• Professional adhesins engage in complex functions such as molecular complex assembly, cell wall maintenance, signaling, and surface amyloid formation.

Conclusions:

• Adhesins, particularly professional types, display remarkable multifunctionality through unique structural adaptations.
• Understanding adhesin structure-function relationships is key to deciphering microbial pathogenesis and intercellular communication.
• Adhesins share similarities with other multi-activity proteins but possess specialized features for their roles.