Two repetitive, biofilm-forming proteins from Staphylococci: from disorder to extension

Abstract

Staphylococcus aureus and Staphylococcus epidermidis are an important cause of medical device-related infections that are difficult to treat with antibiotics. Biofilms, in which bacteria are embedded in a bacterially-produced exopolymeric matrix, form on the surface of the implanted medical device. Our understanding of the molecular mechanisms underlying the initial surface attachment and subsequent intercellular interactions as the biofilm matures is improving. Biofilm accumulation can be mediated by a partially deacetylated form of poly-N-acetylglucosamine (PNAG) but, more recently, the role of bacterial surface proteins is being recognized. Here we describe the structure and function of two S. aureus cell surface proteins, FnBPA and SasG, implicated in host interactions and biofilm accumulation. These multifunctional proteins employ intrinsic disorder for distinct molecular outcomes. In the case of FnBPA, disorder generates adhesive arrays that bind fibronectin (Fn); in the case of SasG, disorder is, counterintuitively, used to maintain a strong extended fold.

Versatility of Biofilm Matrix Molecules in Staphylococcus epidermidis Clinical Isolates and Importance of Polysaccharide Intercellular Adhesin Expression during High Shear Stress

“…First, the G1363T mutation in aap of A1-35 is found within the lectin domain, which may function in initial adherence to plastic or to other proteins/glycoproteins ( 72 , 82 ). However, it is difficult to envision how this mutation could facilitate increased cellular interactions as the Zn 2+ -dependent homophilic bonds occur between the G5-E domains within the B region but not within the lectin binding domain ( 88 , 89 ). Second, growth inhibition resulting from inactivation of GlcNAc 2-epimerase has been documented in many Gram-positive species, including S. aureus and S. epidermidis ( 74 ).…”

Seeing Keratinocyte Proteins through the Looking Glass of Intrinsic Disorder

“…Despite the few reports to date, the importance of IDPs in cutaneous biology can be expected to be the rule, not the exception. Intrinsic disorder is likely integral to the conformation and function not only of numerous endogenous keratinocyte proteins but also in therapeutically counteracting biofilm proteins of skin bacteria, e.g., Staphylococcus epidermidis , and oncogenic proteins of keratinocyte-tropic papilloma virus [ 25 , 29 ].…”

Interactions between Macrophages and Biofilm during <i>Staphylococcus aureus</i>-Associated Implant Infection: Difficulties and Solutions

“…Biofilms formed by MRSA strain-derived proteins tend to be ica operon-independent [25] . S. aureus surface proteins, including autolysins AtlA [26] , fibronectin-binding factors A/B (FnBPA/B) [22] , serine-aspartate repeat protein (SdrC) [27] , S. aureus surface-associated protein G (SasG) [28] , biofilm-associated protein (Bap) [29] , and accumulation-associated protein (Aap) [30] , promote biofilm matrix development and maintain its stability. In addition to these, eDNA exists as a conserved component in the biofilm of different bacteria genera.…”