Fig. 1. Amino acid sequences of Sar1p, Sec31p and Pmm1p with their budding yeast and mammalian homologues. (A) Protein sequence alignment of Sar1p in S. pombe (Sp), accession number M95797 (d’Enfert et al., 1992); Sar1p in S. cerevisiae (Sc), accession number A33619 (Nakano and Muramatsu, 1989); and SAR1A in M. musculus (Mm), accession number P36536 (Shen et al., 1993). (B) Protein sequence alignment of Sec31p in S. pombe (Sp), direct submission, accession number CAA17835; Sec31p in S. cerevisiae (Sc), accession number NP_010086 (Goffeau et al., 1996); and the Sec31 protein in H. sapiens (Hs), accession number AAf67836 (Tang et al., 2000). (C) Protein sequence alignment of Pmm1p in S. pombe (Sp), direct submission, accession number AL132984; Sec53p in S. cerevisiae (Sc), accession number NP_011141 (Goffeau et al., 1996); and phosphomannomutase 1 in H. sapiens (Hs), accession number NP_002667 (Hansen et al., 1997). Sequence alignments were generated using ClustalW and displayed using Boxshade. Black boxes represent identities and gray boxes represent conservative substitutions. *The S7N, E72K and G80D mutations in the Sec31-1 protein and the G27S mutation in the Sar1-1 protein are marked with an asterisk.