Table I.

Conserved sequence motifs of the ADPGlc-dependent α-1,4-glucosyltransferases from plants and prokaryotes

 The plant enzymes are divided arbitrarily into three classes based on their known subcellular locations or, in instances of uncharacterized proteins, their high degree of sequence similarity to such characterized enzymes. Soluble enzymes are those such as DU1 that are exclusively or nearly exclusively located in the soluble phase. Granule-bound enzymes are those such as GBSSI, i.e. the product of awx gene, that are exclusively found in the granule fraction. Dual-location enzymes are those such as zSSI that are present in significant amounts in both the granule-associated and soluble fractions. Conservative substitutions are noted when they fall into the functional groups defined by Dayhoff and Orcutt (1979), which are AGPST, ILMV, HKR, DENQ, FWY, and C. Invariant residues are denoted by asterisks under the plant SS consensus sequence, and rare exceptions to the designated consensus are underlined. Numerals refer to amino acid positions beginning at the first ATG codon of the open reading frame; exceptions are Ta SSS and Ta SS, for which the complete cDNA sequences are not available. The number of nonconserved amino acids adjacent to each conserved motif is indicated. Full references for each sequence are listed in Methods.