Figure 2
From: Genomic analysis of membrane protein families: abundance and conserved motifs
Number of TM-helices in Pfam-A families of polytopic membrane domains. Shown are the number of Pfam-A families of polytopic membrane domains with a given number of TM-helices. Only families with more than 20 members were counted. The green bars indicate numbers from all studied Pfam-A families and the yellow bars those from the Pfam-A families that are annotated as transporters, symporters, and channels.