Fig. 3.

Amino acid sequences of membrane-spanning domains containing GxxxG and/or GxxxG-like motifs, for GpA and other membrane proteins from viral and neuronal origin. The amino acid residues of the putative TM domains are shown as upper case letters and flanking sequences are shown as lower case. Glycine and alanine residues in GxxxG/A motifs are in bold. HIV-1 consensus TM sequence (according to Shang et al. [59]); ScoV-S: SARS coronavirus spike protein; APP and ErbB4 are γ-secretase substrates; presenilin-1 (PS-1) and anterior pharynx defective protein-1 (APH-1) are components of the γ-secretase complex; p75: neurotrophin receptor protein [149]. For other abbreviations see text.