Periscope Proteins are variable-length regulators of bacterial cell surface interactions

Area of Science:

• Microbiology
• Molecular Biology
• Bacterial Pathogenesis

Background:

• Bacteria adapt to dynamic environments, including the human host, through cell surface modifications.
• Protein length variation is a newly identified mechanism for bacterial surface alteration.

Purpose of the Study:

• To identify and characterize a widespread bacterial surface alteration mechanism termed "Periscope Proteins."
• To investigate the role of protein length variation in bacterial-host interactions.

Main Methods:

• Analysis of long-read genome sequencing data to identify potential Periscope Proteins.
• Structural analysis of tandem domain arrays in bacterial surface proteins.
• Comparative genomics to assess the prevalence of Periscope Proteins across bacterial species.

Main Results:

• "Periscope Proteins" are characterized by tandem arrays of similar domains, forming elongated structures.
• Variation in the number of domains dictates the projection distance of N-terminal ligand-binding domains from the cell surface.
• Over 50 distinct Periscope Proteins are predicted, including those involved in host colonization and biofilm formation by pathogens.
• Periscope Proteins exhibit reduced sequence divergence between adjacent domains, challenging typical protein folding rules.

Conclusions:

• Periscope Proteins represent a widespread mechanism for bacterial surface adaptation.
• Length variability in Periscope Proteins is crucial for regulating interactions with host surfaces, other bacteria, and the immune system.
• This mechanism offers new insights into bacterial pathogenesis and survival strategies.