Fig. 2: The S. elongatus T4PM contains minor pilins required for natural competence.

a Heatmap of protein sequence homologies between T4PM and competence proteins of S. elongatus and other strains of cyanobacteria. Gray cells indicate no homolog in the corresponding strain. Strains organized according to 16S rRNA gene phylogeny, inferred by Maximum Likelihood. Nodes supported by a bootstrap ≥ 70% (n = 500) are marked with a red asterisk and strains that are known to be naturally competent are marked with a blue plus sign. b Genomic organization and RB-TnSeq insertion loci for two sets of genes essential for transformation. For each these coding regions and flanking sequences, the number of sequencing reads for insertion-mutant barcodes in selective (top boxes) and non-selective control (bottom boxes) conditions is shown for one representative experiment. c Transformation assays performed on deletion and complemented strains of the pilA3 and pilW, and rntA and rntB loci. For each locus, both open reading frames were deleted then complemented separately and together. WT S. elongatus PCC 7942 served as a positive control and the fully complemented strains to which no DNA was added served as negative controls. The assays were performed with three independent clones for each strain and yielded identical results. Source data are provided as a Source Data file.