Figure 2.

Sequence similarity network (SSN) analysis of Rrf2 superfamily of transcriptional regulators using SPD_1448 as query (InterPro Family: IPR000944) with an alignment score of 43. SSN clusters with greater than seven metanodes are shown and ranked according to the number of unique sequences in each SSN cluster (with one being the largest number of sequences) and arranged from upper left to lower right by decreasing numbers of sequence nodes (each node contains sequences that are 80% identical over 90% of the sequence). SSN clusters for which there is a biochemically characterized, functionally characterized, or a SwissProt-validated member (indicated by the yellow circle) are highlighted by “cluster #,” and those containing validated members of known structure are further highlighted by “cluster #.” SSN cluster 6 (node cluster rank 5) harbors SpSifR characterized in this work. See text for additional details and Tables S1 and S2 for a complete list of all clusters, singletons, and associated UniProt identifiers in this database. Bs, Bacillus subtilis; Ec, Escherichia coli; Mt, Mycobacterium tuberculosis; Rl, Rhizobium leguminoserum; Sa, Staphylococcus aureus; Sc, Streptomyces coelicolor; Sv, Streptomyces venezuelae; Syn, Synechocystis.