Fig. 1. Domain profiles of all PX-domain-containing proteins. Proteins were selected from the SMART database (Schultz et al., 2000), aligned, and unique proteins are shown (proteins with >80% homology were excluded as redundant or orthologous). Where appropriate, the human version is shown. Species abbreviations precede the accession numbers; At, A. thaliana; Ca, C. albicans; Ce, C.elegans; Dm, D. melanogaster; Hs, H.sapiens; Mm, M.musculus; Nc, N.crassa; Os. O.satvia; Sc, S.cerevisiae; Sp, S.pombe; Tb, T.brucei brucei; Um, U.maydis. The residue at the at the equivalent position to Arg58 of p40^phox is shown as the standard single letter amino acid code in each PX domain. Domains with a basic residue (R or K) at this position are suggested to bind 3-phosphoinositides, whereas domains lacking a basic residue are predicted to bind other phosphoinositide species (see text).