Indel frequencies in different structural regions of proteins. Frequency distribution of indel events in the four secondary structure categories helix, sheet, turn and no structure. The background distribution is the relative fraction of amino acids residing in each structure among all analyzed proteins. Error bars were calculated by , where Ni is the total number of indels in structure i.
de la Chaux et al. BMC Evolutionary Biology 2007 7:191 doi:10.1186/1471-2148-7-191