Solution NMR structure of Se0862, a highly conserved cyanobacterial protein involved in biofilm formation

Biofilms are accumulations of microorganisms embedded in extracellular matrices that protect against external factors and stressful environments. Cyanobacterial biofilms are ubiquitous and have potential for treatment of wastewater and sustainable production of biofuels. But the underlying mechanisms regulating cyanobacterial biofilm formation are unclear. Here, we report the solution NMR structure of a protein, Se0862, conserved across diverse cyanobacterial species and involved in regulation of biofilm formation in the cyanobacterium Synechococcus elongatus PCC 7942. Se0862 is a class alpha+beta protein with alpha alpha beta beta beta beta alpha alpha topology and roll architecture, consisting of a four-stranded beta-sheet that is flanked by four alpha-helices on one side. Conserved surface residues constitute a hydrophobic pocket and charged regions that are likely also present in Se0862 orthologs.