Figure 1.

Positional cloning of AtGPI8-1. A, Fine mapping of AtGPI8. The atgpi8-1 mutation was mapped to the upper arm of chromosome 1 between molecular markers AW9 and AW13. The number of recombinants obtained is indicated. Markers are positioned to scale. The corresponding BAC clones and the location of the AtGPI8 locus (At1g08750) are indicated. B, The structure of the AtGPI8 gene and the position of mutations. Boxes indicate exons and thick lines introns. G to A substitution in atgpi8-1 results in Arg₄₂→Gln₄₂. Location of the T-DNA insertion for atgpi8-2 is shown. C, Alignment of Arabidopsis AtGPI8, S. cerevisiae GPI8, and human PIG-K predicted protein sequences. Identical residues are colored black, similar residues are colored gray. Residues labeled with an asterisk are conserved, those labeled with a colon have conservation between groups of strongly similar properties, and those labeled with a period have conservation between groups of weakly similar properties. The conserved amino acids in predicted active sites are marked by circles. The position of the missense mutation in atgpi8-1 is marked with an arrow.