Fig. 4.
Electrostatic surface potential and amino acid distribution at the surface of the EspB hepmateric structure. A) Electrostatic surface potential of heptameric EspB. The exterior of the heptamer and interior of the pore calculated at pH 7.5 with PROPKA and APBS (+/−10 KBT/e). Electronegative and electropositive surface areas are colored in red and blue, respectively. B) Amino acid distribution at the surface of heptameric EspB. Amino acids are colored by type with positively charged amino-acids (Arg and Lys) in blue; negatively charged (Glu and Asp) in red; polar amino-acids in purple (His, Asn, Gln, Ser, Thr); hydrophobic (Ala, Ile, Phe, Leu, Val) in yellow and others (Cys, Gly, Met, Pro, Trp, Tyr) in grey. The surface of the exterior (left) and the interior (right) are represented. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)