β integrin alignments (amino terminal end of the molecules). Amino acid sequence of AmItgβ2 aligned with representative β integrin sequences. Atypical absence of cysteines (yellow, numbered) from positions 8 and 9 suggests orthology between AmItgβ2 and Podocoryne IntB (PcIntB). Structural features including the MIDAS motif (DLSXS, underlined), transmembrane region (long wavy line), membrane proximal motif (short wavy line), and two NPxY/F motifs (double underline) are conserved. The ADMIDAS motif (DDL, underlined) is changed to EDL in AmItgβ2. An arrow indicates the position where a deletion was made in the sponge sequence (OtItgβ1) to facilitate alignment. Abbreviations and database accession numbers for sequences used in the alignment are: Acropora AmItgβ2 (AmItgβ2; EU239372); Podocoryne IntB (PcIntB; AAG25994); Acropora AmItgβ1 (AmItgβ1; AAB66910); Human β1 (HsItgβ1; P05556); Strongylocentrotus βG (Urchin SpItgβG; AAB39739); Strongylocentrotus βL (SpItgβL; AAC28382); Ophlitaspongia βPo1 (Sponge OtItgβ1; AAB66911).