A non-native glucosyltransferase comprising at least one amino acid substitution at a position corresponding with amino acid residue Leu-428, Ala-472, Ala-510, Leu-513, Met-529, Phe-607, Asn-613, Gln-616, Ser-631, Gly-633, Phe-634, Thr-635, or Phe-951 of SEQ ID NO:62, wherein the non-native glucosyltransferase synthesizes alpha-glucan comprising 1,3-linkages; wherein the non-native glucosyltransferase has: (i) an alpha-glucan yield that is at least 10% higher than the alpha-glucan yield of a second glucosyltransferase that only differs from the non-native glucosyltransferase at the substitution position(s), and/or (ii) a leucrose yield that is at least 5% lower than the leucrose yield of said second glucosyltransferase; wherein the non-native glucosyltransferase comprises a catalytic domain that is at least 90% identical to residues 55-960 of SEQ ID NO:4, residues 54-957 of SEQ ID NO:65, residues 55-960 of SEQ ID NO:30, residues 55-960 of SEQ ID NO:28, or residues 55-960 of SEQ ID NO:20; and wherein an amino acid position of the non-native glucosyltransferase corresponds with amino acid residue Leu-428, Ala-472, Ala-510, Leu-513, Met-529, Phe-607, Asn-613, Gln-616, Ser-631, Gly-633, Phe-634, Thr-635, or Phe-951 of SEQ ID NO:62 if the amino acid sequence of the non-native glucosyltransferase can be aligned with SEQ ID NO:62 or the subsequence positions 55-960 of SEQ ID NO:4, said alignment having at least 80% amino acid identity, and said amino acid position of the non-native glucosyltransferase directly aligns with amino acid residue Leu-428, Ala-472, Ala-510, Leu-513, Met-529, Phe-607, Asn-613, Gln-616, Ser-631, Gly-633, Phe-634, Thr-635, or Phe-951 of SEQ ID NO:62 in the alignment of. wherein the non-native glucosyltransferase synthesizes alpha-glucan comprising 1,3-linkages; wherein the non-native glucosyltransferase has: (i) an alpha-glucan yield that is at least 10% higher than the alpha-glucan yield of a second glucosyltransferase that only differs from the non-native glucosyltransferase at the substitution position(s), and/or (ii) a leucrose yield that is at least 5% lower than the leucrose yield of said second glucosyltransferase; (i) an alpha-glucan yield that is at least 10% higher than the alpha-glucan yield of a second glucosyltransferase that only differs from the non-native glucosyltransferase at the substitution position(s), and/or (ii) a leucrose yield that is at least 5% lower than the leucrose yield of said second glucosyltransferase; wherein the non-native glucosyltransferase comprises a catalytic domain that is at least 90% identical to residues 55-960 of SEQ ID NO:4, residues 54-957 of SEQ ID NO:65, residues 55-960 of SEQ ID NO:30, residues 55-960 of SEQ ID NO:28, or residues 55-960 of SEQ ID NO:20; and wherein an amino acid position of the non-native glucosyltransferase corresponds with amino acid residue Leu-428, Ala-472, Ala-510, Leu-513, Met-529, Phe-607, Asn-613, Gln-616, Ser-631, Gly-633, Phe-634, Thr-635, or Phe-951 of SEQ ID NO:62 if the amino acid sequence of the non-native glucosyltransferase can be aligned with SEQ ID NO:62 or the subsequence positions 55-960 of SEQ ID NO:4, said alignment having at least 80% amino acid identity, and said amino acid position of the non-native glucosyltransferase directly aligns with amino acid residue Leu-428, Ala-472, Ala-510, Leu-513, Met-529, Phe-607, Asn-613, Gln-616, Ser-631, Gly-633, Phe-634, Thr-635, or Phe-951 of SEQ ID NO:62 in the alignment of.