Figure 6. Comparison of the proton exchange rates of E^rnsΔN and E^rnsΔNΔC.

(A) Normalized proton exchange rates of E^rnsΔN (Arg194 – Ala227) and of E^rnsΔNΔC (Arg194 – Thr221) for all NH groups identified in the spectra (see Fig. 3C and 5C). (B) The amino acid sequences of the E^rns membrane anchor (E^rns), the N-terminally truncated protein E^rnsΔN, and the N- and C-terminally truncated E^rnsΔNΔC are numbered according to the full-length E^rns protein. The amino acids of E^rnsΔN and E^rnsΔNΔC are displayed in different fonts depending on the value of the proton exchange rate of the corresponding peptide NH group. NH groups with a proton exchange rate above of 0.5 are shown in bold face, while those with a proton exchange rate below 0.5 are in standard font. The underlined amino acids were not detected in the CLEANEX spectrum and therefore do not show any significant proton exchange. Unassigned amino acids in the ¹⁵N-HSQC spectrum leading to a general lack of information about their water accessibility are presented in lower case.