InterPro domain: IPR044161

In plants, sucrose synthesis involves just two enzymes: sucrose-phosphate synthase (SPS) catalyses the synthesis of sucrose-6F-phosphate (Suc6P), which is then hydrolysed to sucrose by sucrose-phosphatase (SPP) [ 1 ]. This entry represents the sucrose-phosphate synthase (SPS) family. In Arabidopsis there are 4 SPS proteins, including AtSPSA1 (At5g20280), AtSPSA2 (At5g11110), AtSPSB (At1g04920) and AtSPSC (At4g10120). It has been shown that the four SPS proteins are functionally redundant in processes that are important for plant growth, vegetative and reproductive development, and nonstructural carbohydrate metabolism [ 2 , 3 ]. This entry also includes bacterial sequences.

1. New complexities in the synthesis of sucrose. Curr. Opin. Plant Biol. 6, 208-14
2. Characterization of multiple SPS knockout mutants reveals redundant functions of the four Arabidopsis sucrose phosphate synthase isoforms in plant viability, and strongly indicates that enhanced respiration and accelerated starch turnover can alleviate the blockage of sucrose biosynthesis. Plant Sci. 238, 135-47
3. Over-expression of an arabidopsis family A sucrose phosphate synthase (SPS) gene alters plant growth and fibre development. Transgenic Res. 17, 181-92