Figure 6.

Lineage-specific expansions of paralogous gene families in archaea. The vertical axis shows the number of members of the indicated COGs. (a) COG0477, permeases of the major facilitator superfamily; COG0531, amino-acid transporters. (b) COG1145, ferredoxin. (c) COG2101, TATA-box binding protein (TBP), a component of transcription initiation factors TFIID and TFIIIB; COG1405, Brf1 subunit of transcription-initiation factor TFIIIB and transcription-initiation factor TFIIB. (d) COG1708, 'minimal' nucleotidyltransferase catalytic subunit; COG2250, 'minimal' nucleotidyltransferase accessory subunit. Species abbreviations are as in Table 1.